Because he fits the same kind of rage-inducing game-play as Teemo, who has a devil skin and is often referred to as Satan, so it resonates with players very well.
I myself can see Shaco going down to Georgia.
It's because he's Hot you silly billy.
Please make shaco a less serious skin that you can use to mess around with and have fun. All of his skins are serious and dark he could use a mixup or an idea for a more serious skin idea make him Krampus for a Christmas skin. Please take a less serious skin in consideration.
Shaco players would accept any skin at the moment, even if he were to get a skin it should be a legendary. Almost 3 years with no skin.