I'm not convinced the problem is a lack of affordable housing so much as there's a lack of people who can afford housing. Extreme wealth and income inequality are deadly.

Is it antivaxxery, or is it that they think only rich people should have the option?

Probably both.

Or even the first half of the second amendment.

Perhaps he means "no true scientists", and by "true scientist" he means only those who support his peculiar beliefs.