Financial institutions lent money to borrowers who could not afford the loan they were given.I don't think they were doing their jobs well. The same goes for insurers.
One reason the insurance industry is so poorly run is that tax incentives are given to businesses to offer generic health-insurance to their employees. Discrimination according to individual cases is needed, and that is not what has been happening. And when they do individually discriminate (both lenders and insurers), they (being conservative, incompetent, scientifically-illiterate, etc.) ignore well-established important factors such as IQ and the various personality factors -- factors that are known to be determinative of social outcome, and more predictive than past-performance (credit-ratings, etc.).
If they are unable to do their jobs any better than that, then the market should be allowed to have its way with them, just as it did the dozens of second-rate silicon-valley VC firms -- and their, in-turn, poorly-discriminating limited-partners -- that created the internet bubble. Why? Because it makes way for the more-competent.
[Edit: Anamax just pointed out that there was government "encoruagement" in these lending decisions, and that other institutions then took on these poor-risk loans. I think the general principals apply: 1. where the government distorts the market, it causes problems; 2. wherever there is freedom in market decisions, whomever finds himself holding the bag has no-one but himself to blame.]