I'm guessing at the end of the day it all comes down to money.
I think you can get more people (paid!) into the Fieldhouse than you can into the Montgomery County gym and I don't think the politics of the region is such that the Northern Kentucky schools (Pendleton County east) will vote to switch to a site further away.
The only reason to switch would be a discussion on the competitive balance of the region--and if it is an unfair advantage to Mason County. While it is undoubtable an advantage, history tells us that more often than not--it is about the players and not about the gym the game is played in.
Just my two cents.