Drivers as a group are integrated into Uber's operations, but an individual driver is not. Nothing at Uber depends on a certain driver being available. Contrast that with most non-contracting jobs where operations depend on an employee being at work and doing their job.
Obviously there is no right of control of Uber drivers. They can choose to accept a contract or not, with no repercussions if they choose not to accept. The fact that the contract has clearly defined terms such as who to pick up, where to go, etc. does not mean the driver isn't contracting (since doing a job that has clear terms is the definition of contracting...).
Other than the 'short-term' aspect, Uber drivers are pretty clearly contractors by that definition.