Re #4: really? How long do drivers with <4 stars last on the platform? (If [1] is correct, they don't last at all, because they get booted below 4.5).

All else equal (and many say all else isn't equal here of course, though that argument cuts both ways), a system with SOME accountability is better than a system with none.

[1] http://uber-partners-static.s3.amazonaws.com/chicago_uberx/f...