I'm not the GP but I would suppose this comes down to if you have a philosophical objection to cities being engineered or not. I personally think that they should be. If the quality of life of citizens of a city is better served by having limitations on this kind of short-let activity, then I think it's reasonable that city managers should have the ability to impose those limitations.
If you believe in Laissez Faire, or that the market should be allowed free rein to shape or society, you would perhaps disagree.
While I can agree to some extent to this being the metric optimized, this metric depends on who gets to be a citizen. For example, the situation when the city becomes too expensive for particular class of people and they move out leads to increased in quality of life of remaining citizen, but people (not me) usually express negative views on this.
Poor people leaving a city increases the quality of life for (richer) people that remain? That's not the obvious result of gentrification. I didn't say cities should optimise for quality of life, but quality of life should be an important consideration in the generation of policy. Other factors like cultural diversity also need to be taken into account, as well as mixing people with different income levels. I have found apartments in Berlin, for instance, that I was unable to rent because they had maximum income caps (and very low ones).
These groups of people aren't playing on a fair field in the first place.
The citizens, who live and work in attractive city, pay hefty taxes to make the whole thing possible - running the public transport, collecting the garbage, keeping the running water and sewage operating.
Obviously taxation policies and city budgets vary a lot from place to place, but it's very common for these things to be funded by income taxes on the citizens salaries - which is fine with the citizens, but then why should to tourists get to come in and freeload off all the nice things paid for by those taxes?
In a parallel universe where all these services were paid for by taxes on property values or rents, I would agree with you - whoever wants to pay the most per night can have it, but in the real world the market is already skewed to start with.
Tourists spend out of proportion to local citizens? Most towns welcome tourism, even advertise for it. I'm guessing its because businesses thrive, tax revenues rise, and the community prospers.
Yes. It varies (hugely) from on place to another, but typically there is a state income tax, and also sales taxes and property taxes that go variously to the city, county, or possibly state. It's quite possible that a person might pay, say, 1/3 of their taxes to these non-federal entities.