In NYC the money is in the medallion, not the fares. If a driver buys a medallion he or she used to be able to count on them going up significantly an retiring on the resale. No, with Uber, medallion prices have dropped to the point some people are under water on a 500k medallion. There is also some evidence medallion prices were drive up at auction to increase the value of all medallions and thus allow owners to borrow more on the medallion since it's increased in value. They used to be a low risk collateral since no more were being made and if someone didn't pay you could repo the medallion and resell it. In NYC, cab companies don't hate Uber, IMHO, because they are taking fares but because it is driving down the value of the medallion.
90K works out to $45 an hour for a 2000 hour year. I wonder how Uber calculated that. Was it drivers actually working 2000 hours or taking the average earnings/hr and multiplying them by 2000 to get the annual figure. In the later case, the number is very misleading because drivers might work more in surge times but not during slow periods, slanting the average to higher earnings.