Hmm think about it a bit, I figure steam would have a certain percentage cut if it were to become available so that'd be less money for Nabi and Hampoorino. I mean, I think few people even actually spend real money on this game so taking away percent of said money would just be kinda bad.
It'd be convenient for the players. Would be inconvenient for devs.
I'm leaning to the unsupported side, TB's only sources of income nowadays seem to be 3d items and toriprime/vip. So yeah, hamp's needs a bit of moolah to release 5.0 and keep the servers up too.