Thing with Aatrox is that the guy basically leaps in, and if he can't outright kill his opponent, he is as dead as a roadkill.
Akali, despite all the nerfs, is still at least somewhat viable through the midgame, but Aatrox? He's horrible early game, he's horrible mid game and late game, when he should shine and his kit should somehow contribute - he fails utterly.
Unless he gets fed like fuck (and let's be honest, every champ is competitive when hyperfed), or his enemies ignore his existence entirely, he won't be able to do shit.