The logic you're using here depends on deliberate vacancy; as soon as you concede that investors let out properties, you force them to compete in the market for housing with all the other supply.
I'm speculating here, but I'm guessing you haven't been month to month rent in a while..
EDIT: you seemed to have tried to redirect the question to this "always buy up more land as an appreciating asset", when both can be true. "Buying that land is an appreciating asset (we haven't made much more I'm aware)" and that "forming an asymmetrical power relationship with the renters improves owners life" are mutually beneficial activities
Or is the argument that merely building more houses isn't sufficient?
(Also presumably you could build an infinite amount of houses, but the land itself is somewhat of a fixed supply...)
Yes. The central thesis of the blog post is that increasing the housing supply solves the housing price issues.
And other people in this thread are going: "Uhh, well actually, have you considered that this is the fault of wealthy investors, and/or collusion or something"?
Anything to distract from the extremely simply and obvious idea that building more housing causes prices to fall.
Car loans have been a thing. And they attach to depreciating asset.