Why is it that, whenever any high-profile rock bod tries to use their position to make a positive contribution to this sorry-ass world of ours, everyone immediately turns on them and starts chucking around terms like “preachy”, “pompous” and “self-righteous”?

I’ll tell you why: It’s because, in our primitive Neolithic brains, these “do-gooders” are assumed to be betraying some ridiculous romantic notion of what a rock star “should” be – i.e. a self-centred, nihilistic pr*ck whose only concerns are getting wasted, getting high and getting laid. Oh, and if they’re really cool, starting the odd ruckus outside a nightclub.

I don’t know where this infantilist ideal comes from, but I’d guess it’s the same bit of evolutionary hard-wiring that makes so many animals fight it out to become the dominant male of the pack, combined with a wistful touch of vicarious living by proxy on the part of Walter the Softie-style rock fans and critics who prefer their sex, drugs and violence kept at a suitably safe remove.

But if we just took a step back and really thought about it, wouldn’t we see how ridiculous it is that we heap such opprobrium on people trying to use their celebrity currency to buy a better deal for Africa, or promote fair trade, or save the rainforest or whatever, while retaining a sneaking admiration for people whose main extra-curricular interest is getting themselves arrested?

Look at it this way: If a rock star is approached by an organisation like Oxfam, they have two choices. They can either say “Okay, I’ll step up and get involved and do the right thing, even though I know I’m going to take a load of flak for it, and it may well leave my rock credibility in tatters”. Or they can say: “Sorry mate, I’ve got a reputation to protect. People expect to see me brawling in the street at 3am, and I can’t risk damaging that hard-won brand for something as trivial as world poverty.”

Who, in this scenario, is the bigger man? Who is the braver, and most deserving of our respect? And, above all, why do we continue to put our faith in the other guy?

I know all our primal, atavistic instincts scream out to us that Keith Richards is cooler than Bono. And in our narrow, defiantly adolescent interpretation of the word cool, he undoubtedly is. But, music aside (cos, luckily for Mr Vox, that’s not what’s on trial on here) which one really deserves our respect, and which our ridicule? The one who tries to strongarm world leaders into doing something about the scar on our conscience that is Africa, or the one who’s getting whacked and falling out of trees a good 45 years after he really should have put that sort of thing behind him? At the end of the day who, ladies and gents, has the biggest cojones?