Why is Osborne obsessed with bonuses?

It is hard to work out what the bankers did to George Osborne. Perhaps he was refused an overdraft at a formative age. Whatever it was, he is taking his revenge, saying that the large British banks should only be allowed to pay trivial cash bonuses. The plan has its political attractions — focus groups tell him no punishment is too harsh for the City of London — but also three significant economic drawbacks.