That might be true for a neighborhood where none of the residents stay for long, but we're not talking about that here. It's like the inn in any small town in the old days. A bit of turnover doesn't hurt the neighborhood, it adds vibrancy and variation.
If anything, I think the typical suburban development where everyone is tied down with 40-year mortgages but nobody is actually home during the week is even more detrimental to the "quality of life of the neighborhood" than a bustling, noisier, more diverse place would be.
If you own a house in a nice quiet street, and someone buys the place next door and wants to turn it into an inn, you'd expect to be consulted about that, right? You'd presumably expect that if everyone else in the street also objects, then planning consent for that business should be denied. If your inn analogy holds, then AirBnB provides no such opportunity for consultation.
The problem of high ratios of short-term occupants destroying communities is well known. The canonical example in the UK is student lets - landlords buy up properties close to universities and let them to students, over time the long term residents are forced out, leading to more and more student housing. These areas attract crime and other social problems because the community is vacant. This is why many councils in the UK restrict the number of HMOs (Houses in Multiple Occupancy) in a given street or area, presumably this happens other places too.
There are good reasons for regulating something like AirBnB or Uber, and it will happen, it just takes lawmakers a little while to catch up.
So it all seems to depend on the ratio of long-term residents to short-term residents. In college towns, the balance shifts dangerously close to the short-term side. But do we have reason to think that AirBnB poses the same danger? Has there ever been a residential neighborhood where AirBnB clients comprise any more than a small fraction of the total population? Yes, some people are renting out entire apartment buildings, but that neighborhood probably has a hundred other apartment buildings, too, with several thousand residents in them.
A neighborhood is whatever its members make of it. If people don't like to have an inn next door, they have every right to speak up against it, organize if possible, and make life hell for the innkeeper so that he moves someplace else. But I'm not sure whether we need the heavy hand of the law to get involved in this at all. In your college town example, what are you going to do? Force students to live at least 5 miles away from campus? Nope, gotta make do with the people you've got, even if it means constructing a new funky subculture just for the student-heavy neighborhood.
I do agree that we need some sort of regulation. But I think those pages of law will be better spent on requirements of safety, taxation, etc. Even a proper enforcement of the fire code will probably wipe out a large percentage of the AirBnB listings.
There's been a few HNers that have shared bad stories of what happens when an AirBnB landlord is letting an apartment nearby. You get short-term stayers who are in town to party and you don't get much sleep when those kind of people are around. 'Bustling, noisier' is alright when you're talking market day, but not so good when it's 2am.
And if you talk to people who live next to inns, they don't usually rate it as a net positive, particularly if the establishment serves alcohol. Intoxicated people make all sorts of messes that they don't clean up.
People tend to attract the attention of police when they make a lot of noise at 2am in a residential neighborhood, even when they're making noise on their own property. I don't see how it would be any different for AirBnB customers.
If the property is not suitable for partying at night, there should be a clause in the rental agreement (and corresponding details on the AirBnB listing page) that clearly says so. Someone like me who prefers a quiet night might even want to filter listings by that condition.
If anything, I think the typical suburban development where everyone is tied down with 40-year mortgages but nobody is actually home during the week is even more detrimental to the "quality of life of the neighborhood" than a bustling, noisier, more diverse place would be.