The German Frankfurter Algemeine Zeitung (FAZ / http://www.faz.net) also has thoughtful comments. I used to think it was something about the community but at this point it seems more related to moderation. You don't see a lot of trolls on the site.
Given that it's FAZ, I suspect all they need is a check that the comment is correctly punctuated, uses the subjunctive, and consists of 3 paragraphs written in 2 sentences :)
