For many years, the ACC tournament was in Greensboro period. That was just where it was. I think 1976 was the first one to be elsewhere. Then it started moving around a little bit but mostly remaining in Greensboro. Other regular sites were Washington or Landover (near Maryland), Atlanta (home of Georgia Tech) and Charlotte (near Clemson and pretty close to Wake, Carolina, Duke and State). Tampa was a bit different b/c it's not particularly near either of the Florida schools. In recent years, it's not had a "home" place, and I'm guessing that will continue.
The ACC football championship was in Jacksonville, FL, and there's not a team there either.