The royal family does not much go in for the vulgarity of emotion.

Princess Diana was expected to tolerate her husband’s infidelity in dignified silence, not go crying to Panorama. Her children would, in turn, be expected to walk dry-eyed behind her coffin. The family still mostly takes its lead from the Queen’s constitutional obligation to conceal her feelings, recognising that her rockiest moments have come when asked to reveal more than is comfortable – during Scotland’s independence referendum, or when the unexpected national wave of grief over Diana’s death left the family looking dangerously stiff. The younger royals have pushed the boundaries by discussing their mental health, but raw, unfiltered emotion is still regarded as suspiciously bad for business. Imagine the concern, then, at the Duke and Duchess of Sussex’s insistence on showing some.

Prince Harry’s outburst this week against a tabloid media he feels has trashed his wife is said to have been made against aides’ advice, and the statement certainly reads like he wrote it himself. Announcing a landmark legal case against the Mail on Sunday, over its publication of a private letter from Meghan to her estranged father, the prince raged that the couple would not endure “painful” intrusions in silence. Having lost his mother, his greatest fear was watching someone else he loved become “commoditised to the point that they are no longer treated or seen as a real person”.

The bad news for the Sussexes, however, is that this is exactly what celebrity culture does. They are part of an industry based on real lives being tidily repackaged for public consumption and sold on for profit – or in the Windsors’ case, public subsidy – and one in which feelings are little more than an inconvenience. “I used to read magazines when I was little and see all these Hollywood people break up and they didn’t feel like real people,” TV presenter Maya Jama explained this week, talking about her public breakup with the grime star Stormzy. “And then when you’re in that position, you’re like, ‘Oh shit it’s very real’. Everybody just sees it as entertainment.”

The private lives of celebrities – which is essentially what the young royals are – have become another part of the show, with actors berated if they won’t spill their guts about their private lives in interviews to promote the movie. Buy a cinema ticket, or pay for a princess’s expensive house renovations, and punters expect to own a piece of you.

Yet there’s something creepy about the clamour for the Sussexes to put out; to cough up more “proper” pictures of baby Archie – none of those coy Instagram shots, revealing a tiny hand but little else – and quit whining about invasion of privacy. The argument is reminiscent of drunk suits braying at a lap dancer they don’t feel has gone far enough for the money; so what if Meghan wants to keep some things private, to maintain at least some kind of boundary? She took the cash! She doesn’t get to choose! Somewhere beneath all of this, meanwhile, lurk uglier assumptions that this particular princess – a mixed-race American divorcee from an ordinary background – might be fair game in a way other royal brides were not.

Frogmore Cottage, the Duke and Duchess of Sussex’s home: ‘Buy a cinema ticket, or pay for a princess’s expensive country house renovations, and punters expect to own a piece of you.’ Photograph: REX/Shutterstock

The royal family cost the nation £82m in the last financial year. It’s an obscene amount of money for one family and doubtless most of us could envisage better ways of spending it, but boils down to £2.65 per taxpayer per year. How much of someone’s intimate family life anyone should expect to buy for the price of a takeaway coffee is a tricky question. But as a rough guide, the devil offered Faust eternal life in exchange for his soul.

There is no guarantee that the Sussexes’ novel court case will succeed, still less that it will solve a journalistic dilemma that is as much moral as legal. This isn’t one of those landmark cases pitting privacy against the public interest – it’s hard to see what higher cause is served by knowing exactly how upset Meghan was with her father – but nor is it a classic tale of journalistic malpractice.

The Duchess’s privacy was invaded not via a long lens, rifled dustbin or hacked phone, but by her own father, who shared the letter with the newspaper after his daughter’s friends criticised him in a magazine article, and one suspects it’s the personal betrayal that really stings. (The couple claim the letter was edited to make Meghan look bad, but their case is primarily based on a mix of privacy, copyright and data protection legislation rather than libel law; if he can’t be persuaded to stop talking about what is obviously a difficult relationship, the aim is presumably to put whatever her father says off limits.)

The closest parallel is perhaps with the cricketer Ben Stokes’s attack on the Sun for revealing details of a family tragedy that happened before he was born. Although it was a matter of public record in New Zealand, and another relative apparently tipped off the paper, Stokes’s argument that his mother shouldn’t be forced to relive such memories just because her son is famous struck home. It’s easier not to think about the human fallout of a juicy story, just as it’s easier not to think about the relationship between a plastic-wrapped pork chop and a live pig, but that doesn’t magic it away.

So put aside, just for a moment, perfectly legitimate questions about whether the eco-conscious Sussexes take too many private jets or Harry is overly sensitive. Strip away the impossibly gilded lives, and what’s left is the product of two damaged childhoods; the motherless son and the woman whose father failed to show at her wedding. For those who want their money’s worth, the pound of flesh they paid to see, here it is in all its naked glory. But it’s the crowd, not the people stripped bare before them, who seem diminished by the sight.

• Gaby Hinsliff is a Guardian columnist