I've been skimming the interview, and it seems to me that it's supposed to be about this guy than about the show. Then again, it is a reality show, so that line gets awful blurry. That said, he didn't seem to be speaking on behalf of the network, the show's producers, or any of that. Given that that's the case, I'm not really sure he ought to have been fired over it. I'd say he should watch what he says more carefully, but that's purely practical advice, akin to advising people not to walk down the wrong alleys lest they be mugged. Obviously, I disagree with what he said, but in the context of his own beliefs and feelings, I'd rather he be an honest bigot than a liar. At least you can engage the former.
I'm really leery of tying a person's employment to their actions off the job - this comes off as a higher-profile equivalent of firing a teacher for being photographed drunk or something. I know that being on a reality show makes your personality a kind of inextricable mascot for the show itself, but I'm afraid I have to endorse the bigot here.
Not that I think the network ought to be legally required to keep him on the air. Provided they're still paying him in accordance with their contract as if he were not suspended, they're meeting the major obligation of an employer, and they generally shouldn't be obligated to broadcast material they don't want to.