The question discussed here is 'is it morally OK to boycott an artist's work because you don't like his views'?
The obvious answer is - it's your money and choosing not to pay and see a movie is well within your power and even moral right.
Of course, if you boycott Card for not agreeing with his views, you should boycott a LOT of other artists, as well.
Certainly everyone from more than 200 years ago; back then, they had views that make Card's look like politically correct central.
Otherwise, isn't the attitude somewhat hypocritical?
SIGH. Except your question is wrong.
The question being discussed, is it morally OK to boycott an artist's work because of his ACTIONS? Not his views. His ACTIONS.