Yes, gay marriage will end democracy, just like it did in the frozen anarchic wastelands formerly know as Canada!
Personally, I think you can enjoy a person's work without sharing their points of view - like the art, not the artist. Nowadays plenty of people are gay for very found of H. P. Lovecraft's work, but he was racist and mysogynist. And wasn't Henry Ford openly anti-semitic, to the point that he received an honor from Nazi Germany before they twirled their mustaches and announced to the world that they were evil? Will you choose your car based on that? (Note: That was a rethorical answer, but try to answer anyway.)
That said, if your disagreement with someone's points of view are stronger than your enjoyment of their art, boycotting it could be a good way to get your point across.
(I don't buy the "it's just a game" defense - gamers are all passionate about saying that video games are the brave new media and people just don't understand its myriad complexities, and then the moment it's the easy way out they all cling to this. Nothing is just a game, or a song, or an image - everything is a picture of everything that lead to it.)
Particularly, I don't get Live and my 360's just been bricked, so fortunately this moral quandary shall elude me.
EDIT: Dammit, the one time I skip two pages' worth of posts and you guys already beat me to Lovecraft.