I have encountered a few people who do argue that government regulation caused the economic crisis. It seems to be the dominant understanding in the conservative media in the United States, possibly elsewhere. The reasoning goes something like this: people in government wanted to redistribute wealth by building up impoverished minority communities, so they incentivized otherwise responsible banks to lend money to people who would not have qualified for loans and punished banks that did not meet certain minority quotas.
Banks responded to this pressure in the only way they could by giving out loans to minorities who then defaulted. Banks couldn't change the government initiatives, so they bundled bad loans with good to try to control the damage and save the economy, but too many minorities were irresponsible. The government then made the problem worse by adding even more regulation on banks, slowing the economic recovery and extending the recession.
I don't personally subscribe to this, but it does seem to have a lot of weight with a certain crowd. It's also used as an example of how minorities and government are the source of other problems in the country, so the only way we can solve the problem is through deregulation, giving more freedom to the financial industry, and ending any sort of affirmative action.