If you have a low rating, Uber offers tips to improve it such as not slamming doors, being ready for pickup, etc. I think it’s also easily found in the Help section of the app.

Based on what I've read here, your passenger rating depends on a lot more than simply "don't be a jerk".

Right, you have to be there at your pickup point, you shouldn't slam the door, you shouldn't be a creep. Not very hard.