True - it benefits Uber immensely from a tax perspective (and benefits?) for them to be independent consultants. It's also harder for independent consultants to unionize.
Its going to be brutal on Uber (and Lyft) when the IRS recategroizes all of those drivers as employees, and both companies need to cough up the employment taxes they should've been paying. It happened to Fedex (their Ground division) [1].
I'm not a lawyer - is this a done deal? With FedEx they were working full time, right? If someone is driving for both Uber and Lyft, isn't it hard to say they should be an employee of one or the other?
[1] http://www.forbes.com/sites/robertwood/2014/08/27/fedex-misc...