It has downsides (like redlining, for one thing) but those downsides already existed in the traditional cab model, so it's at least not worse. Given the problems upfront ride pricing caused for drivers I think it's reasonable for it to go away, even if it's slightly less convenient for me as a passenger.

Ideally the problems with abuse of ride cancellation can just be solved via universal methods that apply to uber, lyft, AND traditional cabs. There's plenty of data available so it is feasible to use that data to police abuses of the system.

Why not? I certainly don't want to be driven by somebody who doesn't want to drive me and hates my guts for being forced into driving me. I'd rather he refused and another willing driver pick up the job.