This is just in lower elos. It doesn't work in gold or higher (meaning that really, it just works on new players mostly). His ganked are telegraphed with easy to avoid cc, to actually do damage he needs to hurt himself (unlike YI) and can't use skills while fighting since they just lower his damage output and survivability, if you don't build any tank you won't survive, also his damage is incredibly hard to output agaisnt good players with good positioning. His only redeem is his superb sustain, which need 3 hits to be procced, making aatrox weak to opponents with heavy cc (like riven, renekton, darius and like 70% of the champion rooster at level 3).