User blog comment:UsoppThePotato/An idea for critical strikes./@comment-4956864-20131002202203/@comment-5266525-20131002222912

Crits are the only thing keeping AD marksmen together as a class because it gives them the triple multiplicative scaling that makes them carries. They can't be removed because there is no suitable replacement, to put it bluntly.

CSC not quite as egregious as evasion, anyway. With evasion the difference between best-case and worst-case scenarios was an entire autoattack. With CSC, the difference between success and failure is only a little bit of damage.