Most are generic anons but in general it seems like there's a culture of keeping your account and not just creating throwaways for single posts. There are some

Most are generic anons but in general it seems like there's a culture of keeping your account and not just creating throwaways for single posts. There are some advantages of that for the user, like being able to flag and downvote, not being filtered (posts from new accounts that sign up and post immediately have a higher chance of getting killed), and in some minds the credibility that comes from a long standing high karma account. And having people want to keep their accounts encourages better behavior because you don't want the account banned. I think all this does have an effect that makes the discussions better than they would be in forum with more ephemeral accounts.