I'm not sure what you're driving at. Visit their website. See where the only words on the page are, "Everyone's Private Driver™"? I think it's pretty clear what they're selling.

And in the case of Uber Taxi, they comply with all legal requirements for a Taxi service.

I use Uber all the time. Regardless of marketing slogan, most people in SF use it like they would a car service or taxi. It's not like the private cars are Bentleys, although that might be a cool option.