Yeah man, TB is really severely lacking in AoE options. Oh wait ...
Notice what i wrote "this would make it somewhat more viable for creep farming from RANGE".
Since he is extremely squishy, and all his other aoes in fire mode are centered around him, he need to get in close and personal to use them. Fireball is is only ranged dmg spell in fire mode. Also its called Fire BALL not BOLT!
Alright, fine, I'll say a little more...
First, Circle of Fire is ranged in a sense, and furthermore it can be cast and left to burn the creeps whilst TB goes fishing or takes guitar lessons, doesnt really matter.
Second, why do you need range to farm creeps? They're never that scary, and TB is best of anyone at annihilating them, in either mode. He's squishy, sure, but c'mon... Creeps?
Third, who cares what it's called...? I could make an equally strong case that they rename it the Confetti Missile on the grounds that it would be amusing.