As long as it means a critical approach from the left wing in terms of other people in the left wing. All you leftwingers should quit the limp-wristed apologetics and face the fact that this movie was shitty through and through.
In terms of it 'doing what it intended to do'... I have to disagree. Its intention was marred by its presentation, which was to provide a framework for justification of American socio-cultural trends. It didn't do this. In fact it bearly held itself together thanks to the half-assed satire and unexplained leaps of logic that Michael Moore (aka 'the fictition') presented. He never 'connected the dots' to provide a direct correlation to anything, and as a result the entire thesis is loose if not non-existent.
They let this dummy win the Academy Award because it looked great for the republican fascists who could then claim that 'there are critics' and that 'they are recognized by and large'.... however shitty and limited these critics might be. So really Bowling For Columbine was a victory for the right wing because it made the left wing look so awful by default.