[accrual]

I think popular subreddits tend to support more toxic behavior, especially those easily accessible by keyword and more so the defaults. They invite anyone and everyone to post. "Niche" subreddits tend to be smaller groups and seem more self-moderated. Sometimes you can find these in the sidebar of the subreddits you're interested in.

Reddit definitely didn't start this way. In many ways it was similar to HN in that it was a small group of technical users, but it grew into a public forum for all topics. The demise of Digg was another factor but is arguably small considering Reddit's popularity today.

Reddit is an immensely useful resource if you know what you're looking for.