I don't think Uber is a good company, but I also don't think they are exploiting drivers. Even if you do, it is less exploitative than trapping drivers into a system by forcing them to prepay for the right to drive. Choose whichever you think is less exploitive when you need a ride, but don't pretend taxis are some noble system.

Less exploitative is clearly better. If you don't like Uber, make something better or lobby for Uber to change, but don't wish for things to go back to how they were worse.