Oh, and not to mention it encourages people to become well accustomed to that specific champion so they can earn the right to buy that "Special 100+ win champion skin", and really, I wouldn't mind buying some money on Riot points to help support the game, but there is nothing I want to buy.
On the other hand if Riot says, hey there is a way to separate yourself from everyone else with this "100+ Win Champion Skin" that you can "Earn" compared to simply just having money and buying it, you have to show that you've "earned" the right to buy this skin.
Just a thought, thanks!