In my 5+ years, I tend to agree with you; there are occasionally little spats that I see, but by and large-- I'd never have known about all of this "bad" stuff if it weren't for other people telling me about it.
This is precisely the issue with "bad" stuff. It draws better attention to itself than the good stuff does. All the more reason for Reddit to get control of it if they want to inspire user growth and maintain ad revenue.
If they were to start "doing something about it", it'd likely not affect me in the least.