While I still think HN probably has the better median, the quality of what you're exposed to on reddit is mostly up to you. Ditch the defaults and Reddit's median skyrockets. Ditch some of the more popular non-defaults, it skyrockets some more. Start building a list of well-moderated subreddits with a strong sense of community, and it jumps some more.

Not that you're doing this with your comment, but it has always struck me as odd to treat reddit like it's a single website with a single experience for all users. Yes, there's a base, universal experience, but it's truly up to the user to tailor that experience into what they want. You want memes and fart jokes? There are subs for that. You want to look at breathtaking photos? There are (poorly named) subs for that. You want to discuss why obscure Warcraft character A is behaving so oddly toward Warcraft character B? There's a sub for that. To me, that will always be Reddit's strength.

No matter what reputation it gets, no matter how much shit goes on in the defaults, there's always my little specialty subreddits filled with meaningful content to consume.