I would love to see an analysis on a site by site basis of what they consider trolls and what they consider highly-rated comments. I suspect however it would be found it would align more closely around in-group/out-group than content.
If what you're excluding is political speech of a sort, then someone is going to be able to accuse the system of censorship, no matter where the line is drawn. It's inherent in the system's goals.
Personally, I think that's a point where any system is going to be rightfully challenged and examined critically, but I think it's still worth doing on a greater good basis. Spam filtering works, it makes my inbox a more tolerable place. It's a good idea to extend it to other types of crappy speech that makes other peoples' lives worse.
Also, possibly this comment would be a false positive in some places because I included extreme text as an example.
Applying r/SRS standards to r/RedPill would be an extreme example of this, and a good thought experiment. Could you model what kind of karma score a RedPill post would get on SRS? How would it change what a discussion page looked like?
It's as much of a lost cause as DRM. You can't silence people until and unless you're willing to kill them, and possibly not even then.