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?