>If I buy a house in a neighbourhood that is zoned single family residential, Am I an "inefficient incumbent" because I expect that over the mid-to-long term it will stay that way?
Yes, you are. You're trying to freeze your neighborhood in amber, which is most definitely a sign of an inefficient incumbent.
No, they just bought it with reasonable expectations - expectations, which were priced in the home valuation. If they didn't care about single family aspect, they probably could've found a cheaper house elsewhere.
Also, let's not pretend that AirBnB is progress. It's just a third party that encourages people to start illegal hotels, to earn money for themselves at the expense of their neighbours. This is not a case of local owners having opposing interests to society at large; this is a case of a company enabling some people to parasite on the others.
Who's parasitizing? Airbnb has 38 million users. That's a ton of value being provided! Clearly people want options besides classical hotels. Just because some guests aren't respectful or something doesn't mean the service as a whole is bunk.
Yes, you are. You're trying to freeze your neighborhood in amber, which is most definitely a sign of an inefficient incumbent.