[quote name='javeryh']I just can't believe no one saw this coming.[/QUOTE]
There are two dominating theories out there (there are others, but these are the only plausible ones):
1) Very few folks did see it coming, and banks thought housing prices would appreciate infinitely (an absolutely necessary prerequisite for any ARM lending). This seems plausible since banks were more than happy to package up mortgages into collateralized debt obligations, trading them back and forth as if baseball cards. This is also supported by how cheaply people like Steve Eisman bought credit default swaps from banks for - they thought he was handing them money over, since the principle of the CDS is that they only pay out if the mortgages go bad in significant percentages (which they did).
2) A lot of folks did see it coming, but as long as they made money (and many did), they would let the institution fall on itself. It didn't matter if Bear Stearns collapsed, as long as you could store enough nuts (metaphorically speaking, as these nuts were the outrageous salaries and bonuses of people at places like Goldman Saches) for the winter.
3) A mixture of (1) and (2). Pretty likely, and supported since institutional groupthink dominates financial institutions (i.e., a lot of idiots who follow the flavor of the month, and only a few who stand to benefit from it). Moreover, the first rule of financial institutional demise is that you don't talk about financial institutional demise - the fear of the self-fulfilling prophecy and all that. I.e., if Jim Cramer came out tomorrow and predicted Bank of America was going to crash, if enough people closed their accounts and demanded their funds (that BoA doesn't have the assets on-hand to cover), they would crash. That's the tenuous nature of financial markets - you can't actually *say* shit's

ed up, because then shit will be really

ed up. I think that last sentence gets its point across, even if it doesn't read that way.
If you're a glutton for leisure reading, check out Michael Lewis' book "The Big Short." It portrays what appears to be a realistic picture of the banking industry since the repeal of Glass-Steagal in 1999, and runs contrary to what all of my banker friends say ("everyone saw it coming"). No they didn't, hombre.