That's an awfully strong judgment to make on the sole basis of a $1000 donation to a popular cause (one that won the election, no less). It's not like he was a leader of the anti- gay-marriage movement. If he didn't bring his politics to work, there was no good reason for anyone else to. There's no evidence that his views on gay marriage affected how he treated anyone at Mozilla. Not a single complaint as far as I've heard, and I'm sure that he interacted with a lot of people given that he was a co-founder of Mozilla.

Magnanimity in victory is a virtue for a democratic society. Do you really think that it's good to have political witch hunts every time the winds change on a social issue?