->Charm damage amp traded for raw dmg
-->Landing charm isn't as important as it was before
--->Charm missed? that's okay, you can still kite and poke with Q
In other words, she's easier to play. Noobs and crappy players can just spam auto-target damage with W and her easier-to-hit Q. While never needing her Charm, which actually required skill, experience and strategy to use.
Lower difficulty = higher win-rate
->MS boost in Q
-->R isn't the only way to escape
--->Less chance to get raped/gangbanged in lane,
So she's less punishing for making mistakes. Bad players will feed less than they would have before. Then they become a slightly lighter burden to their team and easier to carry. Admittedly, Ahri was always a safe pick for someone that actually knew how to play her properly, but now she's safe for noobs and skilless players too.
Less intentional feeding = higher win-rate
My final conclusion based on these 2 conclusions would be she's now a worse version of Xerath. Probably good for low-elo players that play on locked-camera and manual spell-cast.