Shaco nerfs...?

My question is why does Riot have to hit Shaco's AP damage as hard as they did. Recently playing with champions such as and and , it showed me how broken these champions can be with 2 items or even just 1 item. 100-0s in 1 second are so common with these champions. With AD Shaco not being as good as it used to be AP shaco became a big thing but riot did not like how fast shaco was able to kill enemies and get away. The description of assassin is the ability to do big damage and be able to get out. Obviously rengar can easily do this and leblanc even more, just when shaco is getting more and more into the meta riot just has to nerf him. It doesn't make sense to me, especially compared to the other BS assassins that are in the game right now.