I don't think that's what led to the '08 housing crisis. Mortgage-backed securities didn't exist because of some do-goodery; they were part of a much bigger rise of unregulated derivatives (including credit-default swaps, which caused huge damage). It definitely wasn't socialism that caused the rating agencies to give implausibly good ratings to tranches of mortgage-backed securities; that was good, old-fashioned short-term capitalist greed.