Why is Sylas so bad

Just cuz a champ is good doesn't mean its not something u juss ff cuz hes to op. He wasn't that strong, but honestly you could juss ban him. They did the same thing to akali and nerfed her to the ground. Ruining a champ isn't good for the people that play the champ, or the community. Small nerfs are ok, but gutting a champ isn't balancing a game. Its saying we as riot balance team messed up and to fix it we are just hard nerfing the champ for an easy fix instead of actually trying to balance the champ?