Any time I see a commentator cite Fannie and Freddie as the leading 'causes' of the Great Recession, I'm very suspicious that it's propaganda against the government, apologizing for and covering up the real issues with Wall Street.
Clearly, Wall Street needs SOME story about the event, and they'd like it to be one that points away from them and the harm they cause - and why not take advantage to attack the government at the same time?
Fannie and Freddie had problems - there are good books on this, and their role in the mess, partly describing a rivalry between the head of Fannie or Freddie and a Wall Street CEO - but it seems to me they were a secondary issue.
Check good books like Nomi Prins' "Other People's Money" for a good history. And note the net effect of the Great Recession on wealth - a recovery which went approximately 100% to the top 1%, increasing the concentration of wealth.
These are from policiy disasters which aren't disasters at all for the few who benefit, but rather great victories.
It's really time to roll back the 'Reagan revolution' of shifting wealth to the top and deregulating too much - another word for 'denying the American people to insure that great fortunes are not used to harm the American people too much'.
That's when the rollback of the FDR banking regulations started - with S&L de-regulation quickly leading to the S&L crisis, the first big banking crisis since before FDR - and it continued under Clinton and Bush. We need to build the political message to de-de-regulate.