And yet their even more highly regulated status from the 1940s through 1990s lead to fewer problems...
The dimension on which regulations are properly measured is not "high" to "low" but "wise" to "unwise." The US has never had wise banking legislation on the national level (consider Canada as a nation with historically wiser banking regulations). I don't think characterization of the housing market as more highly regulated during the 40s to 90s is correct either, and when it comes to national laws and incentives I expect that 1940 will look wiser than 1990 which will look wiser than 2005.
"I looked at what I think of as the food chain that led to the financial crisis, which was that you had individual consumers buying houses they couldn't afford, sold to them by realtors and property people who were competing to sell more properties at a higher price and so on. [...] I thought, hang on a second, classic economy theory tells you that a competitive marketplace is superior because competition provides a diversity of products which is good for the consumer, and it also, therefore diversifies risk. And yet, in this instance, competition has led every single one of these companies to copy each other, which had concentrated the risk. And I thought, Wow, that's interesting. That's specifically what's not supposed to happen."
More here.