"But, the whole industry is interlinked (I freely admit though that I don't pretend to understand the ins and outs of it all though). However, it was the greed of this whole bloated industry which caused the crisis and yet it is institutions such as universities, the NHS, schools etc etc etc which will suffer."
Perhaps we should start closing RAE 4*-rated departments down on the grounds that the University of the Chip Shop was Unclassified. After all, the whole academic industry is interlinked. No? What about closing down surgical units on the grounds that homeopathy is bollocks and they both say they're forms of medicine. No?
If you can think of a means to stop a successful merchant bank paying bonuses on the grounds that a completely unrelated company in an adjacent industry that happens to contain the word "bank" needed to be bailed out, fire away. But it doesn't seem terribly sensible.
Northern Rock went bust because they issued more loans than they took in deposits, and filled the gap with money that needed to be paid back in one year. When those lenders demanded their money back, there wasn't any cash. End of. You can fix this by regulation, but if you limit the mortgages that can be granted to the deposits taken in less a capital adequacy provision, the mortgage market will look radically different. That's why the retail banks needed to be bailed out: they'd been borrowing short and lending long, and the people they'd borrowed money from shut up shop.
I had an exchange of letters with my MP and the treasury in which I said that NR should have been allowed to fail. Pay out the investor protection, and let everyone else see it as a horrible warning: the shareholders are toast anyway. NR had been paying high interest rates for a good reason: they were desperate for deposits (and the same goes, in spades, for the Icelandic scams banks). But Labour didn't have the nerve, and in the process of performing a similar rescue on another high-risk, low-competence operation (HBOS) managed to broker the near failure of a conservative bank (LTSB) that, bluntly, couldn't imagine that anyone could be as stupid as HBOS and therefore naively thought they were getting a bargain.
Meanwhile, the investment banks continued quite happily. They weren't bailed out.