I'm not surprised at all that Uber has introduced a new Bitcoin payment method. This's the age of new technologies and someone has to introduce such things at last. How long will we still pay in cash? We need to look to the future and try new features!!!
Now imagine that in the age of new technology, the commission on a cab ride could be more expensive than the ride! Or if you cancel the trip you will also lose some amount, with the fact that the refund will take a long time!
In my opinion without some network upgrades bitcoin cannot be a convenient means of payment!