There's a gaping hole in your logic: governments that can block your human driver efforts could (would) also block your autonomous vehicles.
I consider that a good counter-argument, but I have thought about it and don't think that will be much of a problem... I think there would be a lot more pushback around most cities blocking self driving car technology than there is to simply extend union rules to ride sharing cars.
After all, self-driving cars should reduce cars on the road and also reduce accident rates, so there are a lot more parties interested in protecting the ability of self-driving cars to operate than there are to protect Uber from unions.
A current test-bed of this is New York City, where the drivers unions want a 50-year ban(!) on driverless cars to protect driving jobs.. note that doesn't mean they don't want self driving cars, they just want someone to have to pay for a butt in seat in the front.