It's bullshit. SF taxis are inefficient and difficult to use. Ubercab solves a problem and calls out just how ridiculous the SF Taxi system is. Instead of fighting to make their business more relevant, the taxi unions fight with regulation.
I use Ubercab a lot. Why? * Because a car comes to me in a few minutes. * I don't have to stand in the rain and wonder if the illuminated taxi light means the taxi will stop or not. * I don't have to wonder if the cab takes cards or if the driver will simply refuse to take them even if his company does. * Most importantly, I don't have to hold on for dear life wondering if I'm going to die before i get where I'm going.
Let's all stand up and say screw you unions. Ubercab is an innovator. SF taxis, be more efficient and you'll win. Otherwise, get out of the way.