I've always had the idea that Reddit was a place where you could say anything, as long as it wasn't illegal. You might get downvoted to oblivion, but you could still say what you wanted to say. While the subreddit they banned was distasteful and cruel, it wasn't illegal.
When free speech is shuttered because people are offended by what they're hearing, it just seems wrong to me. In addition, because that subreddit existed, that sort of attitude was basically confined there. It was a very poor decision to ban it in my opinion.