Private transactions between individuals - none of the government's business!
Bear with me as I oversimplify (I'm really busy, sorry)
A man stands beside a road with his thumb out. A motorist stops and offers him a ride, for some gas and lunch money. They motor along for a while, passenger gets out, pays the driver some cash.
Is this illegal? Uber only facilitates the driver and rider finding each other. Rideshare finder services are not illegal. Why does it become so when money is exchanged? Because a politically connected union uses their government allies to stop competition.
I do freelance auto repair. I have no license, no ASE certifications, the government hasn't approved my abilities to fix cars. Is this illegal? I'm cutting out a professional repair shop who charges three times what I do. Does the pro shop have cause to demand I be stopped?
Hell no. If my client wants to take a chance on my mechanic abilities for a lower price, it's their right and mine to do so. It's a private transaction between individuals, and it's not the government's business.
Anti-Uber actions are driven by protectionism. Period.