When Does a Writer Become too Personally Repulsive to Read?

Orson Scott Card does not raise the question for me, I read Ender's Game, and was not particularly impressed, but he does for a lot of avid readers of SF.

His recent essay equating gay marriage with allowing blind people to drive, and suggesting a fascist state will mercilessly expose children to "te gay" will further conflict those folks who think that he doesn't write crap, particularly when he seems to call for a revolution to promulgate anti-gay discrimination in our society.

Luckily, I find his plotting pedestrian, his characterizations flat, and his writing not particularly engaging, which is which I read Ender's Game 20+ years ago, and haven't read anything else of his since.