The sudden death of a child is like a nuclear bomb detonating in the lives of the parents: the rubble is never cleared. When Horatio Chapple's mother and father were told their son had been mauled to death by a polar bear in Norway's Svalbard archipelago, we can only imagine the grief that consumed them. The 17-year-old had dreamed of emulating his parents and entering medicine; whatever hopes and ambitions he had were terminated by the attack on a Norwegian glacier.

A normal response to such a death is sadness and empathy with the parents. Not so for the evidently delighted Socialist Worker newspaper, whose column, The Troublemaker, constructed an ingenious pun to celebrate his death: "Eton by bear? The inquest begins." The article's final line was even more gratuitous. "Now we have another reason to save the polar bears." The official organ of the Socialist Workers party (SWP) apparently fantasises about an army of polar bears leaving the playing fields of Eton soaked blue with posh blood.

Whenever I encounter callousness and inhumanity dressed up as socialism, I recall the words of the former Daily Worker journalist Peter Fryer. After witnessing the Soviets' brutal suppression of the 1956 Hungarian revolution, he wrote: "Stalinism is Marxism with the heart cut out, de-humanised, dried, frozen, petrified, rigid, barren."

The SWP is expressly not Stalinist, having emerged from the notoriously fractured Trotskyist movement. But its internal authoritarianism – a parody of whatever Lenin meant by "democratic centralism" – reeks of Stalinism. After a cover-up over allegations of rape provoked widespread revulsion, the sect has been reduced to pariah status on the left. That has not stopped it seeming to confirm the common rightwing caricature of socialism. The left, goes this narrative, is really driven by envy and spite towards those of pampered backgrounds.

The "politics of envy" accusation attempts to shut down even the mildest attempts at social justice. It materialises when Labour suggests a 50% top rate of tax for all earnings above £150,000. The right screams "politics of envy" at a mansion tax – while championing the bedroom tax, which falls on the shoulders of disabled people and the poor. When struggling people are expected to empty their pockets, it's just "balancing the books".

But envy has nothing to do with socialism. Take a look at the icons of the SWP: like Friedrich Engels, a prosperous German industrialist; Vladimir Lenin, born into a family of minor Russian nobles; Leon Trotsky, the child of well-off Ukrainian farmers. The British left claims as heroes the likes of Old Etonian George Orwell, the Haileybury College-educated Clement Attlee, and the late Tony Benn – lauded after his death by Socialist Worker as "one of the most important figures on the socialist left in Britain" – the son of Viscount Stansgate, who spent his formative years at Westminster School. The SWP itself is not lacking in privately educated recruits.

I've been on the receiving end of background-baiting myself. I'm no working-class hero and never pretended to be: my dad was a white-collar local authority worker, my mum a Salford University IT lecturer. That said, I never considered going from a Stockport comprehensive school to Oxford as anything to apologise for; but veteran anarchist stirrer Ian Bone has a different take.

In a recent anti-austerity protest organised by the People's Assembly, Bone's Class War crew decided not to target, say, George Osborne or Iain Duncan-Smith, but mocked up an admittedly amusing banner featuring a still of me from a BBC programme clutching a bottle of champagne, adorned with the emphatic words: "Fuck off back to Oxford." Bone is a disciple of Mikhail Bakunin, a 19th-century Russian anarchist whose aristocratic family owned 500 serfs, and of the even more aristocratic Russian Peter Kropotkin.

This background-baiting unites Bone with the vitriolic right, many of whom remain silent about class privilege until it becomes a convenient means to attack a leftwinger. While a socialist of modest means risks accusations of envy, anyone deemed to be of excessively privileged stock who wants a more just society invites the charge of hypocrisy. If you are over a certain level of income, you must support cutting taxes on the rich, hacking apart the welfare state and privatising the NHS. Demand that the state wage war on poverty rather than the poor, and you expose yourself as a hypocrite. Any leftist who does not decamp to an isolated hut, free of all modern appliances, to subsist solely on homegrown vegetables risks being labelled a "champagne socialist".

But socialism is nothing personal: it is not concerned with individuals and their origins, but rather with a system that concentrates wealth and power in so few hands. It advocates a society run on the basis of people's needs, rather than profit for a small elite. The daughter of a dinner lady or the son of an aristocrat should be equally able to embrace this vision. If Queen Elizabeth wishes to abdicate and join the fight against this unjust society, then comrade Liz would be welcome on the picket lines.

That does not render people's backgrounds and class wholly irrelevant. The left exists to champion the needs and interests of working people: to be effective, it needs to be rooted in their lives and experiences. It can hardly achieve that unless it is representative, acting as a megaphone for the otherwise ignored: the supermarket shelf stacker, the nurse, the young black man.

With all political parties ever more professionalised and dominated by the posh and the privileged, it is hardly surprising that the everyday issues of millions are ignored. A government dominated by millionaires is inviting attack when it introduces policies that help its own sort while hitting others – though are cuts to local authorities any kinder, any more just because the man imposing them is Eric Pickles, a man of working-class Yorkshire stock?

The hope of every socialist is to one day free society of the absurdity of class division. No longer would school children be segregated according to the bank balances of their parents. That does not mean despising those born into the upper echelons of the invisible prison that is Britain's class system.

Whoever wrote that Socialist Worker column thought they were being oh-so-revolutionary, so courageously and provocatively sticking it to the man. But all they were doing is laughing at a dead teenager, whose last moments were no less painful or terrifying because of his cosseted childhood. It is socialism with the heart cut out, devoid of the humanity and compassion that must surely underpin it. That might be their socialism. It certainly isn't mine.

Twitter: @OwenJones84