I have to agree, Atlanta isn't really a great sports town. They've lost 2 NHL teams, the Hawks have terrible crowds, and the Braves and Falcons are supported but even they seem to have trouble filling up. Plus I hate to say it but Atlanta comes off as a really bandwagon city. I know to an extent everywhere is like that, but when the Braves and Falcons are sucking, they don't draw well at all.
As far as Georgia Tech, they don't get near the support they used to. Their football stadium isn't really that big and they still struggle to fill it.
I'm with Milo, I'm highly skeptical an MLS team will succeed there.
GT's problem is that their alumni do not stay in the Metro-Atlanta area or even Georgia.