American traders: Obama to blame for economy?

I like to watch the djia at google finance at least once a week, but one thing keeps confusing me: the 'discussions' section seems to be completely filled with people bitterly attacking the current president for every job loss, DOW slide, or other negative economic condition.

I'm confused because these people often know their stuff: if you corner them and ask what caused the economic collapse, they can tell you the story of bad lending, low-rated mortgages combined into larger packages and sold with high security ratings, they might talk about big swings in the giant pool of money by China & India, but all of these things will cover the last 6 years of the housing market.

I can't figure out how they reconcile years of factors leading to a problem with the last 5 weeks of Obama's tenure as President. Shouldn't they be mad at banks for doing terrible risk management, or previous presidential administrations for lack of oversight & regulation of banks?