What's a rating have to do with them complaining about the job? If someone gives them a low rating because of their thoughts on how they work, that person is a jerk.
The fact they're a jerk for rating you low doesn't erase the low rating.
You may well have enough presence of mind that a driver can tell you a bunch of upsetting things and you can get out the car feeling upset and still rate it as a great ride. Alas, many people in the service industry seem to have learned not to expect such insight from their customers.
You have obviously never driven rideshare or talked much with drivers when they're not working.
Passengers will give low ratings for all kinds of insane things, from the cost of the trip (which the driver has no control over), to not agreeing with some random opinion they had, to refusing to do something illegal and/or dangerous. It's nuts. The rideshare companies side with passengers in these cases by default, and there is usually no way to dispute them.
Of course they do - they're not going to get many five-star reviews if passengers leave the car feeling bad or complicit in exploitation.