This happened even in areas where holiday home ownership and rental was common as a business.
The failure of government to grapple with the negative effects of Airbnb is a separate thing. Airbnb are, in fact, in control of their own morality.
I think you'll find that zoning/planning permission is the real bad guy here. That and a failure to understand Adam Smith and implement the ideas of Henry George.
Unless you were the very first person in the entire area to think to do so, then the existence of that very market for you to rent spare rooms on is actually driving up the prices of properties so you have to do so.
It's also driving up the prices of long term rental, because landlords make more money in the short-term rental market. The prices of long-term rental also affect the floor price of permanent ownership.
Consequently it is always likely that one might want at least one more room than is needed by the family. It additionally provides buffer overflow should the pitter-patter of tiny drains on one's resources appear.
In such circumstances renting out a spare room on a longish licence should necessarily reduce rents since now there is an option which is likely to be cheaper. Renting out a spare room for other people visiting ones city should similarly have had a depressive impact on the price of hotels or an improvement in their offering.
Given the inconvenience and reduced amenity one gains from living in a house under multiple occupation there is further no specific reason why it should be the case that this does not more than offset the cash remuneration meaning there is no in principle reason why the capital cost of such a property should increase.
The vast majority of AirBNBs are the entire house or some separate guest cottage. Many are owned and managed by larger companies. Or by people who own multiple houses.
The individual home owner renting out a room so they can cover their mortgage has become more of an outlier.
Airbnb demonstrates that there was clearly substantial demand for "house style" hotel rooms but hotels chose not to provide them. In most hotels where a room is $400 a suite with a space to work, watch tv and cook, might be $10,000. The hotel market optimised for the business man travelling alone to conferences and paid a price for it. Even my favourite hotel on earth does not provide an "ordinary menu" for the nights where you just want to curl up with your loved one and watch a film - it's Michelin star dining or bust.
In most hotels the only amenity that a hotel offers that is "better" than the home experience is a swimming pool and daily housekeeping.
Who, but the richest amongst us, has their bed linen changed _every day_?
If hotels had been built as apartments with no zoning restrictions arbitrarily placed upon them there would have been an option for the hotels to adapt by offering their rooms up on a long lease.