Interesting point. I looked back at the world where no such regulations existed, and I didn't see a perfect market which quickly and efficiently eradicated charlatans and thieves. No, instead I saw a world where people were constantly being preyed upon by the guiled class. I saw a world where the only people you could really trust were those in your close personal circle, and every transaction with a 3rd party, new or known, was rife with risk.
The "regulatory state" didn't come about as a predicted social experiment, it came about by constantly reacting to an endless stream of malfeasance that constantly stood to wreck any possibility of a functioning free market.
Cities and states regulating measurements and fare mechanisms are generally a -good- thing, even when it affects some darling company. For every darling company that wants us to "just trust them to do the right thing, they're good Silicon Valley-types," there are a dozen would-be scamsters plotting how they can take advantage of similar models to make free money. The constant "free market response" is "Oh, well, people will just shop somewhere else." Yes, after having lost their money (some times many, many people losing their money) AND their trust in any company like the same.
The world of figuring cab fares doesn't exactly need to be "turned on its head," it's a well-established practice of livery that's been going back for hundreds of years (perhaps more - I don't know the complete history). Yes, new technology can make it more efficient, but how inefficient is the current system exactly? Is it worth the risk? This is what local communities ask themselves. Why should one company be granted the permissions to step outside of the decision process and state they don't want to follow the community rules?
Every action by a government, and most especially inaction (failure to regulate) picks winners and losers. Failing to regulate pollution levels, cab fares, food safety, etc. make winners out of moderately unscrupulous types and moderately scrupulous types. Certain forms of regulations can make winners out of either the highly scrupulous, or the highly unscrupulous.
Nothing tastes bad to me about not letting cabs just use their iphones to automatically calculate fares from unmonitored and unvetted software. It makes it harder for Uber to make money? Well crap, cry me a river, it's better than making it easier on the thieves - society has chosen that path over millennia.