The average taxi driver wouldn't make it as an Uber driver, only the superior drivers can sustain a 4.6+ rating.

Uber is extremely draconian when it comes to driver quality. Any driver whose average dips below 4.6 is out. Period. That ensures quality and weeds the bad drivers out.

Sure, there are good taxi drivers, but the average driver is horrible. I was comparing them by saying that, say, the 50th percentile cabbie (median), is worse than even the 5th percentile (worst) Uber driver.