I think some of the people saying no one saw it coming are the engineers of this crisis. No one wants to admit they saw it coming and continued to build it -- especially if they benefited from the crisis. It's been argued that the banks created this mess intentionally because they need a large enough catastrophe to be bailed out by the tax payers.
If you acknowledge that you saw it coming, then the next question is, "Why didn't you do something or say something?" When faced with that question, people appear in a very negative light.
And if no one saw it coming, then you can't be held responsible. It's a freak of nature. An act of God. Uncontrollable.
What if I said, "I saw it coming?"
Would you believe me? What's my evidence? How can I prove I saw it coming? If I saw it coming why didn't I say or do something about it?
It's easier to go with the herd and say not only did I not see it, but no one saw it. To have seen it coming and kept going causes cognitive dissonance and it hurts. Avoid it with ignorance.
Anyone with a level head knew there was a housing bubble. But if you're working as an investor, you don't get paid to sit back and watch your rivals get rich while you're waiting for the pop.
Interestingly, the same group of people usually are the ones crying "but facts are facts" when objecting to pure rhetoric (what other people call a plausible alternative hypothesis that is not easily tested by statistical inference).