Ignoring that everything else about reddit is designed to keep people hopping between subreddits and exploring new subreddits is, in fact, demonstrated by the idea that he thinks toxic users will happily stay in their own subreddits and not attempt to spread their toxicity elsewhere.

Furthermore, the fact that I am over here on HN complaining about reddit instead of trying to argue this sort of thing ON reddit should be proof enough that reddit as a "community" has changed so drastically that HN is somehow an IMPROVEMENT.