I'd still want to own the server.
Because even though the neighborhoods are walled off from each other by the software, it's still all under one roof.
Hack a small local community server and you compromise
one neighborhood. Hack mothership Nextdoor and you've hacked
all of them.
P.S. 1 in 4 neighborhoods have signed with Nextdoor?
Seriously? I'd sure love to see some
proof for that boast. (I suspect there's a little finessing going on over exactly
what constitutes a signed-up neighborhood - and how many neighborhoods in the USA there actually are.)
PPS - I fully intend to bring back a classic BBS. That's still on my hot project list for this year.