We all know that it was a failed attempt at humor on his part. And it fails for the same reason that sexist/racist/homophobic jokes, they are made at the expense of other people. If you disrespect so much others, the most normal reaction is that people think that you are an idiot. Basically.

I'm leftist and still think that if he wrote that, Damon is an idiot. But then again, he himself told you that he used the word "faggot" so it seems he is like that with everyone.