Five years ago, before Yewtree was even a sapling, Robert Webb and I wrote some TV sketches about a British superhero called Captain Todger. Captain Todger had awesome powers that he regularly used to save humanity from destruction. He was a superhero in the Superman mode: he just bloody got on with it. No angst, no darkness, no dressing as a bat. It was bish bash bosh: catch the coachload of pensioners before it hits the bottom of the ravine, punch the bad guy’s missiles into the heart of the sun, and extinguish the nuclear reactor fire with a light-speed gush of super-piss.

So what was his kryptonite, what were his weaknesses? Well, he liked a cigar. He liked a scotch. He liked a shag, to be honest. And he was probably slightly homophobic. And he was definitely very sexist. And a bit casually racist – not the full BNP, but maybe he’d flirt with Ukip. He’d also flirt with underage girls. He combined the worst excesses of Jeremy Clarkson, Bill Wyman and your most dodgy uncle or grandparent (to whom, for legal reasons, I attribute all of the inclinations above, other than the cigar and scotch enthusiasms).

But he kept saving the world. Genuinely saving it with his superpowers. For which everyone was understandably grateful. But then he’d squander all that goodwill by telling Channel 4 News that he’d never trusted Romanians and groping someone at a press conference.

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The character amused Robert and me because of the weird quandary he put Britain in: here was someone we couldn’t do without, but who refused to respect our values and, to a certain extent, our rules. He wasn’t evil – he didn’t become a tyrant. He just did what he wanted, which was often unsavoury, and then saved the world. Buoyed up by a sense of entitlement that’s the inevitable corollary of infinite physical strength and being able to fly, he deflected criticism like bullets with the words: “It’s PC gone gay!”

To keep the audience engaged, and hopefully amused, by the nation’s fictional dilemma, we didn’t have him go too far. There were no beatings or sexual assaults. And he didn’t, for example, say “I love Hitler” or tell jokes about Jews craving money. We didn’t want to make him utterly hateful. After all, he only had the power to save humanity – it’s not as if he was good at anything really important, like kicking a ball around or knowing how to make a frock look swanky.

These are the skills that our culture must value most, because we take an inordinate amount of shit from the people who possess them. In the last week there has been much discussion of the public rehabilitation of a fashion designer, John Galliano, who said: “I love Hitler”, and a footballer, Mario Balotelli, who posted the following joke on Instagram about the Nintendo character who shares his name: “Don’t be racist! Be like Mario. He’s an Italian plumber, created by Japanese people, who speaks English and looks like a Mexican. He jumps like a black man and grabs coins like a Jew.” You can probably spot where it starts to diverge from its own initial exhortation.

Galliano, who three years ago advocated genocide on camera – something I’m pretty sure Hitler himself never did – was officially welcomed back into the fashion fold (are folds fashionable?) last Monday at the British Fashion awards, where he presented a gong to Vogue editor-in-chief Anna Wintour. The consensus seems to be that he was going through a difficult time when he made the outburst and so didn’t really mean it. Since then he has undergone drink, drugs and anger counselling and unsuccessfully sued his former employers for sacking him in response to the tirade – so it’s difficult to imagine how he could be more sorry.

Balotelli’s joke (not actually his; somebody else thought of it), which he subsequently defended and then even more subsequently apologised for, clearly isn’t as terrible as Galliano’s pro-Holocaust diatribe – but it’s only the latest in a long line of behavioural screw-ups from the player. He’s obviously a real handful, except on the pitch where he’s failed to score a single goal in a Premier League match since joining Liverpool in the summer. That doesn’t sound very good to my untutored ear – unless he’s the goalie or something.

Let me put my cards on the table: I could not care less whether or not the extremist clothier or the truculent runner-around continue to be employed. And the same goes for their disagreeable colleagues, be they sizeists like Karl Lagerfeld or rapists like Ched Evans. It doesn’t annoy me that they’ve still got work – but it absolutely baffles me.

After all, the jobs they perform do not remotely matter. Fashion and football attract huge levels of publicity and money – billions of people are earnestly interested in them – but they don’t actually matter a damn. It certainly wouldn’t matter if a slightly less skilled trouser-sketcher who has never loved Hitler, or a less deft ball-kicker who doesn’t tell antisemitic jokes, replaced them. Fashion and football would still be massive cash-magnetising column-inch-consuming concepts – there’d just be two fewer arseholes to make excuses for.

I’m not saying that would necessarily be just. Deep down, both Galliano and Balotelli might be reasonable or even good men. But that’s not their image and football and fashion depend on image much more heavily than on sporting prowess or design excellence. The games need to be exciting and the latest collections need to look mental, but there are plenty of unobjectionable people who could ensure that.

Men like Galliano and Balotelli are treated in the same way the west treats Saudi Arabia – as if they possess a commodity so vital to our prosperity that horrendous moral transgressions must be forgiven to secure its supply. But they’re not like Saudi Arabia, or Captain Todger for that matter. Sport and clothes design are no oil or being-able-to-hurl-a-dirty-bomb-into-outer-space.

I don’t believe these two are being protected out of fairness – in recognition of the pressures that might explain or excuse their mistakes. Fashion and football are too ruthless for that. So why are they sheltered in apparent spite of the best interests of the businesses they’re in?

My hunch is that it’s a vital part of how the purveyors of these expensive luxuries sustain their absurd prominence in society. More than lip service needs to be paid to the notion that top footballers and designers are indispensable geniuses, or that whole house of cards – the system by which so many people’s attention and money are captured – will collapse.

David Mitchell’s new book, Thinking About It Only Makes It Worse, is published by Guardian Faber (£18.99). To order it for £12 go to bookshop.theguardian.com or call 0330 333 6846