People with strong libertarian values saw this as disruptive and helping break the Taxi monopolies. This may have been true initially, at least in some regions. (Uber drivers in NZ would tell me they use to work for Taxi services, and most of them made more when they switched to Uber. That was 2 years ago -- wonder if it's still true there).
I remember in Berlin, the laws changed and were enforced in such a way as Uber was just a call service for all the standard taxi companies, so it's the same price whether you use Uber or just flag one down.
The fact is that Uber is just another company and they use their money and position to just ignore laws. In the case of their self driving vehicles, the laws in California aren't even all that insane. They're basic laws around safety and liability for all self driving pilot programs, which other companies have applied for and gotten.
I realize people want cheaper taxis, but drivers need to be able to make a living. Yes, many of them are exploited by their taxi companies that take way too much off the top, but now we see Uber doing the exact same thing -- a bait and switch. It's a thankless job and companies like Uber really exploit the vast majority of them, except in markets where governments have really stepped in to put a stop to it.
There's a reason labour regulation and unions exists. Some of it may slow some business development or keep corrupt people in positions of power, but a lot of it originally started with the idea of stopping things like child labour, unsafe factory conditions and slave wages.