Guest stays free = okay.
Guest pays you = not okay.
The average person can understand that. In fact, most people do. The "benefits" of AirBNB are usually lost on the average person, who cannot understand why someone would rent out their house directly to total strangers.
In High Point, NC they have a bi-yearly furniture market that nearly everyone in town rents their house for two weeks. This has been going on for decades and gave most of the people who did it an extra few thousand a year. It's not as radical as it seems even in non vacation areas.
Vacation spots usually have permissive laws regarding vacation rentals to encourage property owners to rent out their properties during the times of the year they are not using their property. (For example, contrast the permissive rules of Dana Point and Myrtle Beach with the prospective rules of Pasadena and Boston.)
Different considerations apply in communities which are not vacation spots.
Right. Now try to get the average person to care about the distinction.