> Berlin, like most German cities, is experiencing an acute shortage of affordable homes. Rents are rising at a rate of nearly 10 percent a year, even though the city has a rent cap and has introduced one of the strictest bans on holiday apartments - many other European cities also have some kind of regulation.

From that quote I would say vacation rentals are being scapegoated. Rents are rising with one of the strictest bans on holiday apartments.

Affordable housing was a problem before AirBnB was ever conceived.