What else could the defaults be, though? The good communities are smaller and better moderated, but they don't have the resources to police anyone who signs up for an account. As it is they get the users who bother to change their subscriptions from the default, and that's an useful filter.
Nudging the participants in some of the big communities into better commenting behaviour seems achievable (less users go vote in comment threads, most communities manage being self-policing), but driving out the meme generators isn't achievable from votes only. They are what the lowest-common denominator of the user base wants to see, and what they upvote.
On the other hand some of the smaller communities would benefit from more recruitment, particularly of dedicated users, but that doesn't have to come from the frontpage. Tapping into other social networks, via things like twitter sharing and per-subreddit twitter accounts (like StackExchange does), would be a good avenue for that.
Nudging the participants in some of the big communities into better commenting behaviour seems achievable (less users go vote in comment threads, most communities manage being self-policing), but driving out the meme generators isn't achievable from votes only. They are what the lowest-common denominator of the user base wants to see, and what they upvote.
On the other hand some of the smaller communities would benefit from more recruitment, particularly of dedicated users, but that doesn't have to come from the frontpage. Tapping into other social networks, via things like twitter sharing and per-subreddit twitter accounts (like StackExchange does), would be a good avenue for that.