User blog comment:UsoppThePotato/An idea for critical strikes./@comment-5266525-20131002222450/@comment-4296199-20131003022654

You buy crit items to have a chance to deal double the damage. That is pretty significant regardless of the phase of the game. Having that inconsistency of crits could mean the difference between a carry winning a fight it shouldn't win or dying because the crits don't come out soon enough.