Simple, tax their short term Airbnb rental side hustle until they have second thoughts about this and maybe then they rent it instead to a long term tenant who actually needs it like a local student or worker.
The main aspect of Airbnb being attractive in Portugal is that rental laws are very biased to tenants. It is quite literally almost impossible to evict. Also in general civil court cases are backlogged for years.
Airbnb will probably feel like neo-liberal haven for these landlords.
Airbnb will probably feel like neo-liberal haven for these landlords.