To model correctly one tranche of one CDO took about three hours on one of the fastest computers in the United States. There is no chance that pretty much anybody understood what they were doing with these securities. Creating things that you don't understand is really not a good idea no matter who owns it.
If orange trees grew all over the country, you couldn't sell oranges. Do you understand that? So, all our decision making is based upon scarcity or the availability of resources. If we have a shortage of any kind of resource, we put all the labs to work on making substitute materials. People always worry about 'What if we run out of a certain material?', but we have enough technology today to make thousands of different substitutes.