Can we get a crit-based non-keystone rune?

I feel like either an alacrity or hunter (more particularly alacrity) crit chance rune for mid-late game might add to the game. A 10% crit chance would be worth as much gold effifency as the 18% attack speed from alacrity and would open up new builds. ADC's can just go Infinity Edge and Essence Reaver if they mainly want the AD like MF and still get the full benefit of Essence Reaver. A champion could also go three crit attack speed items and rush a 100% crit chance if they feel like it or want to get their damage elsewhere. I feel like it can really add to the variety of builds ADC's can take instead of I.E/ E.R and an attack speed item always.

Other than that, a % crit damage rune like before the rune update would not do bad on a particularly hunter type rune, because that is the tree for more damage and for assassins and so they possibly could build crit too (like they have before) or have crit in their kits. The hunter rune doesn't have any options for those that just want damage and it can give assassins an option of more damage, roaming power, sustain, or item cooldowns. It can also be for ADC's that want a bit more damage late game in exchange for early game pressure.