You seem to have asserted that this type of content regularly makes it to the front page, but in my experience that's not true at all.
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.