Rating of passengers is completely up to the individual driver. It used to be that nobody knew the tipping policy so I never used to fault someone for not knowing. However, given that this has been more broadly publicized and many of us now have in vehicle signage, there's really no excuse. (What? No cash you say? Oh no problem! I have a Square reader right here..).
While we are on ratings..Some of things that contribute to low rider ratings:You make us wait for you, you entered a pickup location several minutes away from the actual one, you're rude ( Do not act like you own the car for 65 cents a mile. It doesn't end well), you make a mess, your kids make a mess, you are LOUD (usually paired with drunk in my experience), you try to take all 500 lollipops from the container with you (seriously!), you steal my iPhone or andrioid charger (it happens more often than you'd think, and yes we notice and put in for a $25 surcharge), and I'm sure there's probably a few others I'm missing.
Its a Golden Rule thing really, treat your driver as you'd like to be treated and you'll get 5 stars everytime.