If that tenant had had a roommate, would that roommate not be consuming the same facilities? If so, would that be morally questionable?

At the end of the day, that tenant is probably paying homeowner's due proportional to the square footage of their unit. e.g. someone with 2 rooms is likely paying twice as much in dues as someone with 1 room.

I know that when I rented the penthouse unit in an apartment building with my father, we were paying almost 2x as much in building dues as the other units in the building, since we has 2x the space. Our roommates used the same facilities we did.