I think it's important to remember that in the current case, we are dealing with a single company doing business as a US corporation, but in the theoretical case, we could be dealing with a peer-to-peer network where the prices-per-ride are determined in the decentralized market. Crush uber with union laws, City restrictions, taxes, and other regulations, and a successor will fill the void which cannot be brought down so easily.
It's not like uber is threatening to disconnect the driver if they don't work, it is entirely an at-will engagement.
Like many unions today, the intent is to cement the power of the status-quo and raise the barrier of entry for new drivers.