Use of a modifier doubles any bindings you would have. Lets say 5-6 on a keyboard (after wasd) and another 6-8 on a mouse, and you have 20 - 30 actions max. And thats stretching it to custom macros just for your team mates. Even then unless your top 0.5% I doubt how effective it is.
The idea that someone can seamlessly use 60 odd keybinds in a PVP environment is ridiculous, even if you could create than many with the pruned abilities we now have.