Subreddits do some things really well. AskReddit became a great community. I was involved in Suicide Watch for a while. and it really was doing some great things.

The problem with Reddit was that it let users make their own reddits. That led to dilution. If PG were to divide Hacker News by his own pattern, we might maintain order.

That said, I'm against it. There's no need yet: the community's fairly intact.