Why Not Make Crit Increase Basic Attack Damage?
Remember when League of Legends had dodge in it? They removed it because it was an unhealthy mechanic that relied more on luck to do well. In that case, why not rework crit chance? Right now, it's almost completely up to chance (there are some deviations depending on how much you crit), and it can make or break a laning phase or a game. A better way to do crit would be to make each 1% of crit increase your basic attack damage by 1%, increased to 1.5% if you have infinity edge. That way, crit basically has the same effect, without the randomness.