I'm familiar with the Greenspan quote, but in retrospect, they didn't destroy themselves. They'd seen the presidence of the savings and loan scandal and seem to have acted as if the government would be there to back stop them. In fact, given the willingness of the government to bail them out one could even argue Ayn Rand was completely right about the whole situation and that they acted rationally by taking on huge risk. If they banks were allowed to fail early and often from their mistakes, the behavior we saw likely would not have happened(for the exact reasons Rand states).