I imagine somebody who's currently employed wants to know that the company is better than the place they're currently at before they'd accept an offer. But sometimes "better" can be a very low bar to clear because their current company might be awful.
In other words, evaluating the candidate by their questions is just bias towards those who are already in good situations. Somebody being unemployed or employed in a toxic environment doesn't mean there's anything wrong with them especially in an economy where companies continue to lay people off at random.