They also have users, a brand, and revenue. They're probably spending all that money on marketing. I'm not going to pretend to be an expert but that's part of building a company. Gotta spend money to make money.
There is no way in hell that loss is going to turn into profit this millenium. Unicorn valuation is basically a very expensive game of hot potato.
They are profitable in the U.S. They are unprofitable world wide because China and India are newer markets and Uber requires scale to turn profit. As they continue to gain market share and overall ridership/driver-ship, they will become closer and closer to world wide profitably.