[ksaj]

It's a more nuanced problem than that. This is how I've understood the problem when discussing foreign ownership specifically (don't shoot the messenger please!):

Our housing prices are wildly high, partially or even significantly, because of very wealthy foreign purchasers who often don't even live in the homes they buy. They jack the price up and sell them to other very wealthy people from their respective home countries. Rinse and repeat. It affects the prices of homes all around the property in tandem.

Basically those wealthy people who aren't contributing to the economy outside the house they bought, are making housing outrageously expensive for the people who do live here, because regular people can't financially compete with the wealthy purchasers that see the home as nothing more than a money maker to trade in overseas properties stacking.