Here is the thing with "sharing" economy - the moment money exchange hands, this is no longer sharing but commercial activity. So you must abide to the regulations. You cannot cherry pick only the rules that suit you.
They've been able to do it to the tune of a tens of billions of dollars valuation. So has Airbnb. Why change now? They'll get their IPO before anyone has to answer for anything, so investors & founders will be happy. Keep running the marketing machine with the "sharing" moniker right until the check clears, and after that, it's the shareholders' problem.
Being immoral can hurt your profits, because customers might be repulsed and boycott you. Breaking the law can hurt your profits, because the government might take action against your business.
Those are the sole reasons why you would avoid doing immoral and illegal things. If the benefit outweighs the negatives, then businesses will do those things. If they don't do it, they will lose against other businesses that are willing to do it.
Fortunately, the downsides can be quite big, which means that most of the time businesses will "stay in line". A huge boycott from the people or hard damaging actions from the government really hurts profits, so it's very rarely a profitable thing to be immoral and break the law.
Drivers pay for the vehicle as well as all maintenance and operational costs. They also pay for insurance. They aren't covered by workers compensation if injured while on the job.
One man's modus ponens is another's modus tollens...
The way I see it is that there is no such thing as "commercial activity". There is voluntary activity of all sorts, and all kind of transactions happen, whether it be through payments, barter or goodwill. If I'm exempt from the ADA when inviting friends over, so should you be when you rent your room on AirBnB, and so should the motel across the street. All exist on a continuum, and the "sharing economy" is now making that continuum more explicit than ever before.
Decreeting that some activity is commercial and subjecting it to government rules merely because it involves money is arbitrary and unfair. Laissez faire, laissez passer.
How can there be no such attribute if there is a continuum of that attribute?
Picking thresholds is not unfair. It's the fundamental way that life interacts with the world around it. You physically cannot examine everything that could affect you with infinite precision.
The job of regulation is not to pick a mythical "perfect" result for every possible case, it's to force a good guideline into place. This is partially arbitrary, and that is okay. It doesn't matter if that fine is $200 or $220, the regulation just needs to work.
What I mean to say is that the attribute isn't categorical, even though it is treated as such in the discussion. I'm also not saying the regulation cannot "work" by picking a threshold, I am appealing to our moral intuition that regulating private behavior is wrong to explain why regulating "commercial" behavior is also wrong.
But how does it explain that? The situations are clearly very different on either end of the spectrum, so you can't directly use the intuition from one end on the other. The only thing you've really shown is that the categorization will be mildly imperfect.
There's rarely such a thing as a perfect category in real life. Arbitrary categories are still categories, and still work with moral intuition, they just take slightly more care around corner cases.
Extrapolating from one case is a bad idea when categories are fuzzy. You find such things as the sorites paradox.
