The #1 thing I hate about low elo ADC'ing are supports hitting/killing creeps
I've been playing ADC again lately and I forgot how annoying the creep stealing by supports is. My support took over half my creeps in my last game and actually was a level ahead of me after it. Due to the players being bad, he still had more cs than our midlaner.
You aren't helping me by hitting creeps. You really aren't helping me by killing them.