Here's why not: Because too much vacancies/transient inhabitants destroys communities.

A lot of shops etc depend on local customers. If there is too small a consumer base, these shops disappear starting a cycle that is detrimental to the neighborhood.

This separated from the assholes that drag their airport suitcases with hard plastic wheels across the pavement at all hours. Have weekday keg parties and all sorts of other shenanigans. Neighborhoods are for living, hotels and other accomodations are permitted for a reason.

The way it all started was people with a spare bedroom, which is fine. Then the residents will make sure that people behave and that the airBnB'ers behave.