It will be hard to write a socially conscious book. Invariably, you will show your bias, and it will sound preachy. That gets old quick.

I've read books like this. The good guys are always right, the bad guys are too evil, and it's unrealistic.

I remember long ago when I first read R. A. Salvatore I laughed in embarrassment at how simplistically black and white it was with respect to the evil dark elves. Somehow I got into it though. Learned to enjoy the simplicity as an escape from a more complex world.

Black and white morality tales can be fun as escapism to a world where life is more simple and straightforward. I'd like to work on one such story. But then I want to write something much more serious also. Something that attempts to show people exactly as they really are. And in the real world I don't believe in evil. Instead misunderstandings, fear, closed minds, etc.

I think the thing about being preachy is the reader feels like they're being treated like a child. It ends up being a difficult thing of who exactly is your audience. What level of intelligence should be assumed in the reader... If you assume too much intelligence they end up cheering on some character who has a lot of traits that the writer personally thinks are very negative things and doesn't want people to adopt. If you're solely trying to entertain, so what? But if something more it becomes a potential problem.

Right now reading about an obese Russian millionaire who's kind of an ass, but is portrayed as the protagonist (Absurdistan). It's light and humorous enough that a normal person should understand to not actually act like him. But I can see people still objecting to the story as he's beating his servants, etc and is still being portrayed sort of sympathetically.