I've only had one 'bad' experience with Uber (driver didn't speak English properly and went to the wrong address and couldn't issue me a refund). I left a low rating and Uber contacted me out of nowhere and proactively offered me an apology and a refund. I also heard they're pretty ruthless about firing drivers with low ratings.
Meanwhile I've had a regular cab driver double-swipe my credit card and one who did a u-turn from the right lane without checking his blind spot and nearly killed us both.
Meanwhile I've had a regular cab driver double-swipe my credit card and one who did a u-turn from the right lane without checking his blind spot and nearly killed us both.