If I were Bottom, I might not quit if my pay never decreased. I'd take the hit on my dignity to continue getting a Director salary for a worker's job...
That's pretty much it for me. There's a lot of complexity in hosting that you don't have to do if you use someone else's instance. There's a risk that their server goes down, but most people who start big servers know what they're doing.
Its also advantageous to join the instance you want to interact most in. Interacting across instances is possible but still a little buggy. It's harder to find communities, and once you do, sometimes posts don't load.
Smart!