The fact that AirTran used to be called ValueJet and that they had an accident in the past, is irrelevant as to whether there is a discussion forum on them.
A discussion forum is someplace for people to voice their opinions, and this can't be done as easily if there isn't a forum.
2 things to consider:
1) American Airlines just had the first deaths on a US carrier since 1997 with their recent crash in Arkansas, - so, following the logic presented, should we remove the FlyerTalk forum on them? I don't think so..
2) There are forums on this board for Tarom Romanian, Sun Air, Aero California, and LOT Polish.... I think that AirTran would get a lot more traffic than all of those combined.