I was excited to try Robinhood until I realized that bad execution on the app side (my side) and on getting order fills (their side) would eat up all if nor more of the benefits. Plus frankly if they were poor at getting you to trade to generate exchange rebates, I have to wonder what else they were doing/planning with your money.
Perhaps its because they don't want "real traders" or "buy and hold" people as their inventory. Given that the users of Robinhood are what they are selling, maybe they can get more for those users if they prove that they are both unsophisticated and active? I know thats the kind of counterparty I'd want if I was paying for order flow.