Riot's logic about Aatrox doesn't hold up to actual gameplay
They said that the changes would make it easier for Aatrox to play from behind. Partially true, if the game goes long enough. However, games almost never go long enough as the game stands.
Furthermore, when you are behind in lane, you are likely zoned, and when you are zoned, its very hard to stack Hellbent, which means you dont have a revive, which means you are an easy target for ganks and for tower dives. This makes it much harder to hold your own when behind or zoned.
Furthermore, in general, playing Aatrox takes a lot more concentration now. You have to constantly be counting or looking at stacks to try to time engagements. Its quite an burden just to be able to have any passive benefits.
Most of the time, Aatrox in play is a bare bones champion with no passive benefits. Let me list everything Aatrox doesn't have:
A shield A Block A Parry A Spellshield Abilty to silence Ability to Blind Ability to slow attack speed Ability to gain bonus health Resistances built into his kit Bonus crits True damage Any armor pen %health damage Ability to boost movement speed Ability to vanish Ability to burn for damage Invulnerability
...and now we can add in, a reliable passive
What does he have? Healing, bonus damage, a dive, a knock up, a slow and a poke and bonus attack speed
However, many champions have all or most of that PLUS some of the above mentioned powers.
This is why Aatrox is weak.