He, like 52% of voting Californians, in 2008, opposed gay marriage. This was a different time: there were various arguments about "civil unions", concern from religious groups, worries about slippery slopes, etc., but we are passed that now -- he no longer holds this belief, and time has proven those concerns to be ill founded. Nobody should be held in indefinite contempt for political positions they once held. If we can forgive Barack Obama for opposing gay marriage, then we can forgive Brendan Eich. You can say that you like his work without having to have endless caveats about how you don't agree with a political position he took twenty years ago that even he no longer advocates.