In your CCP example: I gain nothing by getting convinced one way or the other, and neither does anyone in China gain or lose anything from me getting convinced. Unlike you and your wife's relationship, you and I don't even truly care if we sympathize with each other or not (us being internet strangers and all). Case in point, have you ever done anything for your nearest Falun Dafa crowd? Personally, I don't plan on getting involved with them, even if I have been convinced of the persecution claims (and the same goes for east africa, venezuela, abused puppies, etc).
The fundamental paradox of debating, IMHO, is that debating is inherently a selfish endeavor: a lot of people do it for self-satisfaction, not because they are trying to accomplish something. Personally, I just acknowledge the selfish motive and use debating as a tool for bringing out ideas from others that I might not have thought of myself, so that I can then incorporate those ideas into my own mental framework of the topic.