What kind of investor puts their money into a business which has a decade long track record of losing money and no profits in sight? In a system which is notorious for incentivizing short term gains... It doesn't add up.
Amazon took 20 years (mas o menos) to turn a profit. Tesla took 15ish or so?
A lot of people have clearly latched onto something Jeff Bezos said a long time ago in an interview, which was, "Get big fast." The whole goal with Uber is to utterly crush all competition until they're the only game in town. The only other explanation for Uber is that they're banking on self-driving cars and are hoovering up data from the app towards that goal.
Uber only has one way to win, no matter what, beat every other taxi company. They either do that by running every other taxi out of business, or find their Holy Grail of self-driving taxis.
Do investors have the stomach to fund Uber until either of those things happen, though?