It's no quandary at all, the visitors and the landlords agree. Only a minority disagrees.
If the rate of visitors reaches a rate where where the occupancy rate of airbnbs is makes them less interesting than long term units, congratulations, you have found market equilibrium.
If the rate of visitors reaches a rate where where the occupancy rate of airbnbs is makes them less interesting than long term units, congratulations, you have found market equilibrium.