I don’t think most of us are in a position to actually make money by shorting Uber, as tempting as it is. If nothing else, Uber is so focused on market expansion that they are still not really profitable. More seriously, whenever possible, drivers prefer Lyft, because Uber is note for jerking drivers around. It’s impossible to tell what one is going to make if one takes a drive, the percentage varies too randomly.
Most drivers I run into are logged into Uber and Lyft, with Lyft calls taking precedence. It might be possible for Uber to get drivers to use them exclusively, but they’d have to spend money. Threats and penalties would only further alienate the drivers. As long as there is one other service around that offers even a better deal or interface for drivers, Uber is at risk. I expect them to start trying to buy ride call monopolies any day now.