Who are the people that “seriously question basic market pressure being a thing”? Am I missing something?

Every leftist European nimby party comes to mind.

Just look through the comments on any post about housing or immigration and you will see hordes of them.

There was an article on HN front page a few months ago which stated(paraphrased) "building more housing to reduce prices is a right wing ideology that doesn't match reality" or some such. I'll reply here if I find it.