Especially when those 2nd, 3rd, + properties are being used as passive short term rentals. Observing the state of the housing situation “Hmm there aren’t enough homes for normal families to each have a chance, I should turn this extra property of mine into a vacation rental.” does this make said person a POS?
No. Unless it’s like a family situation where it requires it I think it’s unethical. People live in tents in the park in my city because housing is scarce and wildly expensive. It’s not right to be able to hoard property.
Unfortunately op asked two inverted questions so no could mean not ethical or no not a POS, or, somehow, unethical but not pos.