Honestly, just remove Keystones
I just found out that I'm what's wrong with the game. It's bad for strategic gameplay when a champion's full combo does damage no matter the stage of the game. So, there's no point in fighting it anymore.
Give the people what they want. The people here at least. Make it so masteries are just another version of runes again: Balls of stats. That'll be fun and encourage interactive and strategic gameplay. Somehow.
You're just a gaming company, Riot. What do you know about what we might find fun and interesting?
EDIT: Apparently, I need to clarify. This post is my surrender. I'm done trying to illustrate the merits of keystones and other mastery and item changes.