That's Uber's problem though. Essentially their billionaire investors subsidized car rides for lots of people. Maybe it'll work out for Uber in the long run. Maybe not.
I think the logic is to own the portal to taxis and become a gatekeeper, by being the only app that the user has installed for hailing taxis. So the barrier to entry becomes large because you have to convince people to install your app.
There's still a speed-bump, but it isn't as jarring.