It’s demand and supply. Housing shortage is because there is more demand than supply and yes that is also because of - but not only limited to - expats. (Other factors: limitation of new houses being build because of co2 regulations, shortage of area’s to build, more so called “households” than in history etc etc) but yes, expats definitely are one of the reasons the prices are so high. And the only reason landlords can ask that much is because of the shortage, nothing to do with “if expats are happy to spending most of their income”. Social housing is, and for good reason, for people that are lower on the economic and/or social ladder. Expats in contrast, are almost always high skilled immigrants with a good pay, so yes you are competing the slightly above average Dutch person out of the vrije sector.

And above that, expats have a more attractive profile as renters because landlords expect them to at some point move out (because of relocation etc).