This is why if you have a car salesman you like it's important to give them a perfect rating, including the areas where they're not even mentioned, as the entire survey reflects solely on them. If the question asked how your experience with the Finance Manager was, and you give it a 9/10, it could cost your salesman thousands in bonuses, and have no negative impact on the FM at all.
Drivers have to rate riders before they get their next ride, so every rider gets rated by every driver they pair with.
Lyft states (at least they did) openly that a 3 star rating or below will ensure that the driver and rider are not paired again, and will prompt for a text entry explaining what went wrong.
I don't disagree that the rating system is broken. But it is what it is and it's not likely to change soon.