>...there's absolutely nothing preventing you starting a new subreddit. Except for discovery. If you want to talk about, say, Python, you'll probably go to /r/python. But what if /r/python's mods start sending the sub down the drain? Go to /r/python2? /r/python3? /r/python_lang? New users are still going to go to /r/python and be sucked into a bad community. If they're really invested in discussing Python, maybe they'll find /r/python_lang, but if they're not they'll just bounce off and the entire community won't grow.

IMO reddit needs namespaces. Back in the beginning, there weren't subreddits, just reddit.com (like HN is now), and as reddit grew they created subreddits to divide discussion. I think it's time for another subdivision. This might work well with their attempts to become more of a people-focused social media company: a person can start a subreddit and appoint their own moderators: /r/ranger207/python would be an entirely different subreddit from /r/antihero/python. This reduces the "default name" problem: if you want to discuss Python and search "python subreddit" you'll get both results. You won't automatically assume /r/ranger207/python is better than /r/antihero/python like you would assume /r/python is better than /r/python_lang. Anyway, that's a big digression...