Not to be annoyingly picky, but - Okay, a cause, but root cause? The root cause was people making bad decisions. Downstream of that is bank actions. Even further downstream of that is regulation or lack thereof. (or is Upstream a better word?)
Ok , now I'm just being annoying.
But seriously, get a society where a larger majority believes in personal responsibility and choices with consequences without federal intervention, and you actually do solve the root cause. How we get ahold of that society, I haven't much idea, although I know what it DOESN'T look like - a lot of modern ideas about how to train people on their relations with government.