It helped that they started in places like San Francisco, where the taxi cartel was so absurdly terrible that you'd win fans just by showing up.

I lived in SF when Uber started. We used to call Veteran's Cab because they were the only company that wouldn't ditch on the way to pick you up, but it was completely normal to wait more than an hour for a cab in the dark hinterlands of 24th and Dolores or the industrial wasteland of 2nd and Folsom. An hour during which you had to be ready to jump as soon as the car arrived. Everybody had at least one black-car driver's cell number for downtown use because if they happened to be free, you could at least get picked up.

Uber would have had a religious following of fanpersons even if all they'd done was an estimated pickup time that was accurate to within 20 minutes.