Reddit didn't censor itself because Americans are not accepting of free speech. Reddit started censoring itself to appease corporate overlords. And the only reason those corpos embrace censorship is to stay out of the political crosshairs. How long did /r/jailbait exist before getting shutdown in 2011...and only because it was featured on Anderson Cooper?
That's not true. Reddit "censorship" that is the problem isn't things like banning questionable subreddits. Some of them were stupid. For example they claimed many were banned for "harassment" when there was no way for any subreddit to control whether subscribers harassed people, and it was inconsistently applied only to certain subreddits.
No, the real problem is that now on reddit you get side-wide banned by the administrators for saying words that they've deemed to be unspeakable slurs, regardless of any context. You might want to debate whether it is a slur on a debate subreddit. You might want to talk about how you were shouted at on the subway. You might want to talk about the fact everyone used to use it, and now doesn't. Today, you have to do all those things without actually saying the word you mean. That's the kind of censorship reddit does now: site-wide, unappealable, automated and contextless, based on keywords and not intent.