why was aatrox nerfed?

Before you ask "why?" show some proof that we are actually looking at a nerf.

In my opinion the changes shifted him to the tanky side of top lane champions. He has a self heal mechanic similar to Darius that heavily rewards tanky builds. He also has more damage that doesn't depend on offensive items.

Considering Aatrox ploblems to find a spot in the meta, being able build more tanky while still having relevant damage will definitely help him.