Depends who you mean by "people".
Let's face it Jérôme, even when it is explained, the vast majority of people cannot understand such implications. Hell, even the simple concept of actualisation is very difficult for the majority of people.

I do not say that as an insult, as implying that people are stupid children and should be despised. First, there is nothing despisable in not being among the cleverest of people, provided you don't run for the (vice-)presidency. Second, this is a very narrow field of human understanding. I would probably be unable to understand the implications of events on a variety of subjects even if they were explained in a leaflet, though I believe I happen to be fortunate enough to be in the top centiles of the intelligence distribution (OK, I own it, one letter of the previous sentence is not even completely honest).

So, prospectus notwithstanding, if people who could not understand either the implications or the likelihood of a housing downturns were being agressively advised to put money into such products, I won't place most of the blame on them. I know the libertarian meme of each person being the best placed for making all of his decisions for what it is, a fallacy.
Besides, when you say that people chose to follow the herd, it would be nice to be clear at what the alternatives were. If there is no landlord that lets you in, if you are not allowed to build a small house because of lot sizing, do you sleep outside?

Anyway, in any system, you can't rely on blaming the people. If human nature means that, unchecked, the system will crash, it's easier (terribly difficult OK, but still easier) to fix the system than human nature.

Now if you mean bankers by "people", I'm with you and have been wasting time typing all that ;-)

"It failed because Nacy Pelosi said some unkind things about George Bush in her speech"