When Apple’s CEO came out as gay last week it marked a transformation from efficient technocrat in Steve Jobs’s shadow to would-be champion of a new era of corporate responsibility

Three days before he became the only head of a major American corporation to announce he is gay, Apple’s chief executive, Tim Cook, was in his home state of Alabama, delivering a speech that invoked his heroes, Bobby Kennedy and Martin Luther King, and hinted at ambitions not previously associated with the world’s coolest tech company.

Ostensibly, Cook was there to take his place in the Alabama Academy of Honour, a distinction granted by the state legislature to its most accomplished citizens. But Cook also used the occasion to challenge Alabama’s bedrock conservatism on a variety of awkward topics – race, poverty and discrimination against homosexuality.

Too many people, he said, were being denied the excellent public education he had had growing up in a small town outside Mobile. And it was unacceptable that gay people in Alabama, along with 28 other US states, can still be fired from their jobs because of their sexual orientation. “As a state, we took too long to step toward equality,” he said. “We were too slow on equality for African-Americans. We were too slow on interracial marriage and we are still too slow on equality for the LGBT community.”

It wasn’t the first time that Cook, now in his fourth year as Apple CEO, has worn his progressive politics on his sleeve. At a shareholder’s meeting in March, he stunned the conservative National Centre for Public Policy Research by saying that anyone who objected to Apple’s aim to make its factories carbon-neutral and free of toxic chemicals should “get out of this stock”. In June, he joined other Apple employees at San Francisco’s Gay Pride march.

Now, by coming out as gay and proud in an essay in Bloomberg Businessweek, he has explicitly linked his own sexuality to Apple’s corporate policies and his clear aspiration for a more equal and open society. “The company I am so fortunate to lead has long advocated for human rights and equality for all,” he wrote. “We’ll continue to fight for our values, and I believe that any CEO of this incredible company, regardless of race, gender, or sexual orientation, would do the same. And I will personally continue to advocate for equality for all people until my toes point up.”

Much of the ensuing discussion has focused on the likely effect of Cook’s announcement on public policy, on the career prospects of gay people in the US who remain overwhelmingly afraid to come out to their work colleagues, and on the dozens of countries that do business with Apple while continuing to criminalise homosexuality.

But it is also the clearest possible statement that Cook is stepping out of the shadow of his formidable predecessor, Steve Jobs, and establishing a startlingly different leadership style. Anyone who has followed the company since its renaissance under Jobs may be struck less by Cook’s public declaration of homosexuality than the fact that he is saying anything in public at all. Until recently, Apple has been known for its near-obsessive cult of secrecy. Jobs did not believe in public speeches beyond the presentations he made when rolling out Apple’s new products. He didn’t talk to the media and instructed friends and colleagues not to talk about him in public either. If he believed in workplace equality, he certainly didn’t advertise the fact in speeches to state lawmakers.

When Cook took over, six weeks before Jobs died of cancer in October 2011, it was widely assumed he’d continue the tight-lipped tradition. He was known as a shy, furiously hard worker, cool and technocratic where Jobs had been volatile and design-driven. As Apple’s chief operating officer, Cook had been the man who got the trains running on time, who made sure product releases hit their deadlines and warehouse inventories did not lie idle. People were afraid of him, not because he might blow up as Jobs was known to do, but because he would quietly pummel them with questions and expect immediate answers.

Within the company and Silicon Valley, it was no secret that he was gay. Cook never advertised the fact, but never hid it either. To most Apple employees, his sexuality was not nearly as startling as his habit of sending emails at 4.30am, calling worldwide teleconferences at all hours, gathering his staff on Sunday nights to prepare for the work week, punctuating awkward pauses in meetings by tearing open the wrappers of energy bars and taking almost perverse pleasure in ignoring dinner reservations or sports tickets his staff might have had if he still had issues to resolve.

Little was known about his life outside Apple except that he lived alone in a rented house, did not show off his wealth and was fanatical about physical fitness – his few leisure hours were often spent on hiking trails, on his bike or in the gym. His short-cropped grey hair was said to be modelled on one of his idols, Lance Armstrong.

It would have been daunting for anyone to fill Jobs’s shoes, let alone a classic company number two – shy, meticulous, content to be behind the scenes – fighting the perception that he could never hack it in the limelight. Cook himself declared his predecessor to be irreplaceable. Jobs had founded the company and micromanaged every aspect of its extraordinary success. The company’s divisions – sales, marketing, design, engineering and so on – could afford to work in almost total isolation because only one man needed to know what each of them was doing. The extraordinary secrecy surrounding the development of the iPhone was chalked up, at least in part, to the fact that even senior Apple employees did not totally understand what they were working on.

Cook has taken almost everyone by surprise with his ambition to transform the culture of the company, turning it from a “benevolent dictatorship”, as it was once described, into a more open and interdependent work environment. The new products he’s overseen – an app on the iPhone that enables users to pay for goods by credit card without even turning the phone on, or the much-discussed Apple watch – have involved a far greater degree of cross-departmental collaboration than existed before. He has also committed himself more explicitly to corporate responsibility – on employee rights, the environment and monitoring subcontractors overseas. In the old days, Cook said in an interview last month with Bloomberg Businessweek that preceded his coming-out essay, the culture was “just be quiet, just say nothing, only talk about things that are completed… That doesn’t work in things involving social responsibility… I’m going to be 100% transparent”.

Cook has shown an entirely new side of himself in the past three years – no longer just the icily efficient backroom manager but a man who embraces his employees when he sees them, talks passionately about his political beliefs, puts his money where his mouth is and understands how the power of his position can effect change. Earlier this year, for example, Apple was instrumental in persuading the Arizona state legislature to veto a bill that would have let company leaders with anti-gay religious beliefs practise open discrimination.

Cook’s insight is shared by another Silicon Valley business leader who came out in the 1990s in a much less gay-friendly environment. “If all the lobbyists for the pro-gay Fortune 500 companies talked to their representatives in Congress, it would be done – we’d have national antidiscrimination legislation,” said Tim Gill, who built the desktop publishing company Quark and now heads a political foundation to promote gay rights causes. The real significance of Cook’s announcement, Gill told the Observer, is in places where iPhones are ubiquitous but gay rights barely exist. “Now all these people know Tim Cook in another way,” Gill said, “it gives them a chance to change their opinions and evolve as humans. It’s a wonderful gift he’s given them.”

Cook comes from a working-class world where homosexuality was far from accepted – the mayor of the town where he grew up, Robertsdale, has said he should have kept his private life to himself. “Being gay has given me a deeper understanding of what it means to be in the minority and provided a window into the challenges that people in other minority groups deal with every day,” Cook wrote in his essay. “It’s been tough and uncomfortable at times, but it has given me the confidence to be myself, to follow my own path, and to rise above adversity and bigotry.”

In corporate America, that still makes him a rarity. The Fortune 500 has only 25 women chief executives, five African-Americans and – as of last week – one openly gay man.

THE COOK FILE

Born 1960 in Mobile, Alabama, to a shipyard worker and a mother who juggled parenting three children with a job in a drug store. Worked for IBM and Compaq before being hired by Steve Jobs at Apple in 1998.

Best of times The rollout of the Apple OS X operating system, the iPod, the iPhone, the iPad – all huge successes.

Worst of times In 1996, he was diagnosed with multiple sclerosis,which turned out to be a misdiagnosis but scared him enough to turn him into a fanatical bike rider and a prodigious fundraiser for multiple sclerosis causes.

What he says “If hearing that the CEO of Apple is gay can help someone struggling to come to terms with who he or she is, or bring comfort to anyone who feels alone, or inspire people to insist on their equality, then it’s worth the trade-off with my own privacy.”

What others say “In 2014, it is still news when Tim Cook of Apple becomes the first chief executive of a Fortune 1000 company to publicly say that he is gay. Some day, an announcement like that probably will not be newsworthy, and when that happens, it will largely be because it was news today.”

Columnist Claire Cain Miller in the New York Times