I'm not sure that's wholly true.
I didn't say it would be *easy* for him to do so.
it seems to be VERY difficult to get people to change their minds.
Sometimes yes. Especially in cases where the mindset isn't based on rational data or information.
in most cases, I think it's the person themselves evolving to change their viewpoint. Which is technically the same as what you meant, but I don't think it'll be rapid or dramatic.
I didn't ask for rapid or dramatic.
Given that he's espousing the same views as his church (as I am told, but could be wrong), he's inherently in an environment to maintain his current viewpoint.
All the more reason to send signals to him from outside his current environment, right? Clumsy, probably ineffective, sure. But, you take your chances where you can, right?
In practicality, he's not likely able to change his mind.
When considering ethical and moral action, we have to be very careful to differentiate between what one actually cannot do, and what one can do, but won't. We are responsible for what we can change, and not responsible for the things we cannot.
I *will not* accept the posit that he cannot change. That position validates hate crimes. "I'm sorry, officer, but I come from a culture that really believes this, and I can't change that, so I'm not really responsible..." Nope. Sorry. Not acceptable.
I will accept that Card is highly unlikely to change. He won't change. Confronting him with the wrongness of his ways will likely lead to him becoming defensive and entrenching and pushing back, sure. But, there's a point where he stops getting to use his environment and upbringing as an excuse for being a jerk.
In Card's case with Superman, there is a point beyond getting Card to change his mind.
Imagine a young boy, reading Superman - the character is an icon of Right Action. If the boy likes the comic, and goes looking by more from the author, and finds Card's personal blog? We now have Right Action associated with hateful messages. This is not DOOM! We can teach the young reader otherwise, with luck. But, why have that association possible in the first place? Why knowingly add to the burden?
Even if Card kept his more extreme ideology out of the comic book, maybe he has made himself an unacceptable role model. In the sports world, maybe there is too much money at stake to reliably weed out bad role models, but genre authorship? Not so much a problem.