Seems to me another self inflicted wound by Turkish government on an already struggling tourist trade.
Not according to the Turkish hotel and tourism organisations who have been lobbying for these changes for some time. The numbers of foreign owners affected is minimal when you take Turkey as a whole, and for every Brit, Scandi or German who bails, there'll be a Qatari or Iranian or Saudi who'll take their place.
Barcelona is probably the highest profile city to implement similar measures recently, again under pressure from the hotel and tourism organisations. The council fined AirBNB €600,000 last November due to them continuing to advertise "illegal room rentals", although how they'll enforce it I don't know. It hasn't affected their tourism figures - locals are still complaining that the city is overcrowded with tourists and from my last visit, yeah they're right!
JF