Sure, you could rude and and uber apologist, but they've admitted doing it in the past...
They've done is many times in many markets, and there are many more articles describing the practice.
Perhaps you should educate yourself. There are multiple class action lawsuits against uber **currently** for using this practice. You could be an uber apologist online or you can get in on the cash.
You tell me... why would a driver spend 20+ minutes driving to a pax... only so the driver will cancel a few minutes away BEFORE starting the ride or getting the cancelation. It's a common occurrence in larger markets like LA.
The fact that you AREN'T aware of this common practice just tells me you work for uber.