Drivers are only independent contractors due to poor employment policy from Uber. They work for Uber, therefore Uber do have a duty of care to the users of their service. Now some may say that they only provide the platform similar to Silkroad, however the key difference is that the drivers are representing Uber, in Silkroad's case the sellers were not representing silkroad.

If Uber wish to be seperate from those drivers, they need to provide the customer the chance to choose the driver, and have an appropriate review system.

Uber isn't a marketplace like say Ebay. As such I expect them to be responsible for the actions of "contractors" they appointed to do the job. As the buyer couldn't freely choose the contractor.