User blog comment:Juper0/Solo'able Baron?/@comment-24340503-20140330111537

You pick Renekton, you get a very dominant early-mid top laning phase that transitions into a megatank.

You pick Kassadin (At least, the old one), you get a weak early midlaner who transitions into a super-powerful lategame carry.

You pick Shaco (AD), you get a very dominant early ganking phase that suffers in midgame but turns into a teleporting Tryndamere who's popping carries like zits.

You pick Master Yi, you get a champion who's weak early and susceptible to counter-jungling but has reasonable ganks. With a Yi on your team, you hope that he gets either fed or farmed, and you let him take the kills from the ganks. Then, later in the game, he can solo Baron.

My point is, each champion has its strengths and weaknesses. There is no reason that "I can solo baron" should never be part of a champion's strengths. There will be some kind of tradeoff somewhere else. MeleeADC, who are universally good at soloing it (Once they have between one and two lifesteal items, a somewhat specific build), have bad early games, and they're comparatively awful at dealing multi-target damage like most Mages, or fighters like Riven (Note: Obviously the MADC can deal some area damage, I didn't say they dealt none, that isn't the point), Therefore, in teamfights, they might not bring as much to the table. But they can solo the Baron. Sure it's annoying, but it's just part of what they bring to the table. And it can cost as little as 75g to make sure they don't do it.