[JCharante]

You're assuming people who find reddit results in google only use it as a knowledge base and are only lurkers.

I'd say it's the opposite. Every new message is not new, valuable information. 99% of users are saying useless stuff and people interacting daily are only saying useless stuff that doesn't matter. People using reddit as a knowledge base do still contribute and someone engaged in that subject matter by googling it is more likely to be interested in that subject matter and participate in the community that they've found. Communities are killing their discoverability and turning into a closed-off echo chamber and keeping only their useless users.