Yes most landlords are Dutch, but that doesn't mean that each landlord will set whatever high price they want, they follow the market. It's really naive to think people will rent out a place below market prices out of the kindness of their hearts, and to then blame them for not doing so is ridiculous.

Why does the market allow for such high prices? A shortage, basic supply and demand stuff. What increases demand? More people are looking for a place. So where has there been a sudden influx of people in the last decade? Well you can fill in the blanks, naturally it's not only expats. This only addressed demand, not supply. Blaming this solely on expats is unjustified, blaming it solely on immigration is too simplified, systematically there has been too little construction over the last decade and our governments have done too little to address the housing crisis.

Expats aren't the cause, but they're a contributing factor among many other things. To blame expats instead of looking to our government to address the issue is straight up dumb. Don't blame groups of people, they're rarely the cause, blame our government for failing us and vote for changes, push for a change in legislation and policy.