They are shooting to become "too big to fail". Now the play with bankers, media and politics show that direction. There is surely no other way to change the law in their favor in the U.S., may not be so easy elsewhere.

For that the valuation seems right and may even have to rise. It's all on paper. Think of Uber as a global taxi and delivery-service - basically aiming to become a new monopoly or the strongest player there. Taxi is very fragmented with money going to lots of pockets. Uber is one pocket.