I agree with Bick Mick.   Flying a few thousand miles isn't prohibitive for a lot of us, nor is driving 12 or more hours.   I just don't think many of us want to do BOTH, and that's what would be involved for a lot of people if the gathering were on the northern coast of Calif or in some location in the mountain states that's not close to a sizeable city.

A location not too far from a large population center increases the likelihood that people will be able to carpool to the gathering site.