I'd posit the extreme likelihood that "uncensored" and "not a shit-fest", as time approaches infinity, are mutually exclusive.
"Shit flows downhill," as it were. If some sites are kicking people off who (however one chooses to measure the concept) "diminish the tone" of the site, and some sites are not, it stands to reason the sites that do not will end up collecting the sort of comments that "diminish the tone" over time.