A lot of the people on LW are programmers and thus want to be employeed by software companies. Those generally exist in big cities. Big cities also tend to draw a lot of diverse ideas.

I can talk to someone in Berkely about Circling/Authentic Relating because there are Circling Events in Berlin and there are Circling/Authentic events in Berkely.

I haven't checked but I wouldn't expect to find Circling in Kraków or Malta.

Malta happens to have some interesting properties but I would guess that it would take significant financial resources to build something there.