User blog comment:Qwertyfatcat/A different look on Crit/@comment-10390686-20140211115255/@comment-1330314-20140211120417

By changing crit to Ashe's passive, you're basically saying every champion with crit should wait until they get to 100%, then use their autoattack to poke for potentially a lot more damage. Ashe's passive is to help her trade better in lane to compensate for her weak early game. Champions like and  would become far too strong in lane, as they could time their Q to always land a guaranteed crit, and others like  would have their gameplay messed up, as they only have a short window of time to land their crit in trades.