Voted up.
You actually expressed what's wrong with my idea, and I'm going to have to think about it some more. It doesn't really work as is (it's a bit circular.) I have trouble understanding the mindset of what I perceive as "anti-nice" even when I see it in my family and closest friends, so it's difficult for me to present it in a more positive light.
I don't think it's fundamentally political, really, because before I ever heard of politics, when I was a child, I was relentlessly in favor of happy endings for everyone. Whereas another child in my elementary school relentlessly rewrote stories so that the characters would suffer more, spent more time drawing the bad guys, and so on. It was some kind of temperamental difference between us that showed up by the time we were four years old.
EDIT: This post is pretty flawed, but please read the comments anyway: I'm hoping to rework it into something that catches the idea better.
You can view a lot of value differences along a pro-nice/anti-nice spectrum.
Pro-nice people (I'm one) gravitate to obviously pleasant, lovely, happy experiences. We like kittens and puppies and rainbows. We like transparently "happy" music and transparently "beautiful" works of art and literature. (If you like Romantic poetry and science fiction, but not contemporary novels, you might be pro-nice.) We prefer the positive social emotions, like sympathy, encouragement, and teamwork. We may choose intellectual interests based on the fact that they make our brains feel good. We tend to be drawn towards proposals for making the world wonderful.
Pro-nice people aren't quite the same thing as optimists. An optimist tends to anticipate that things will turn out well, or look on the bright side. But pro-nice people may well hold pessimistic ideas or have melancholy temperaments. Pro-nice is a preference for the positive. A typical pro-nice attitude is "Humanity may be destructive and cruel, but the one time when we're at our best is when we're doing science. Science is lovely. I think I'll be a scientist."
Anti-nice people have a preference for the difficult. They find pro-nice preferences saccharine. They like artistic expressions that have a challenging or negative "mood." They prefer the negative social emotions, like antagonism, sarcasm, and cynicism. They dislike things that have obvious appeal, or things that everyone finds pleasant. As far as social issues go, they take a keen interest in potential catastrophes and what must be done to avert them; they generally aren't drawn to proposals to "make the world a better place."
Again, anti-nice people aren't necessarily pessimists or unhappy people. Anti-nice people prefer to direct their attention to the challenging, the problematic, the worst-case scenario. To an anti-nice person, there's nothing interesting to work on when everything is going smoothly; just liking things or agreeing with people or being contented is rather dull.
I suspect that a lot of conflict can be summarized by the clash between pro-nice and anti-nice personality types.
Are you pro-nice or anti-nice? Have you experienced difficulty communicating with the other type?