I would opt out of uber X if you have an expensive car. It's difficult, but it's possible. If you can't opt out in your market, than you know what you're getting into when you log in and you do have a quasi obligation to accept rides (otherwise log off).
Otherwise, if you're going to not accept rides and cancel others, I can see why Uber might not think you're a good partner. I'm not taking their side, but I can see where they're coming from.
I know people are going to flame me for what I wrote because they're going to say they are an independent contractor and have every right to pick and choose their rides. And that may be true, but then Uber has every right to deactivate you (at will employment) if you are causing an issue for their customers (not accepting rides makes longer wait times and canceling rides leads to irate customers).
If the system isn't mutually beneficial, then just don't log on.