You might be right, but if the requirement for shelter is to not use drugs, why is it the shelter’s responsibility to alter their requirements rather than the person who’s seeking shelter’s responsibility to abide by the requirements? They aren’t owed anything, they’re being offered shelter at someone else’s cost. If I’m hungry and a restaurant offers to give me free food, I can’t then get angry that they have a “no shirt no service policy” and require me to wear a shirt to receive my free food.