I think that is just because Satoshi put "chancellor on the brink of a second bailout" in the genesis block. Clearly he had been working on Bitcoin for much longer and the precursors to Bitcoin had been worked on for decades. So I agree that bitcoin probably wasn't created solely as a response to the GFC but maybe that was the tipping point prompted Satoshi to know it was a an idea whose time has come. Who knows what he was thinking. That might have just been the top headline of the day.