His kit doesn't correspond with itself like it should. Q is wonky, E is wonky, Q->E is wonky, players just walk away from you, players just walk out of your w even when they dont have boots, cannot get ontop of players as a bruiser for some reason, you're a useless sack of shit after you revive from your ult, half the time you get like 200-300 health after your revive because players just kill you so damn quickly, passive is useless as shit, E barely gives any healing from abilities, even when maxed second, forced to build damage because you're useless otherwise. I don't know why I would pick Aatrox over anything else to be honest. I can barely kill the damn intermediate bots for fucks sake.
Also, before someone gives me the "all new champions riot releases are bad for a while" argument, I can tell Aatrox sucks just from his kit alone. His numbers aren't the problem, it's his abilities and how they tie in with one another.