The same article goes on to say that former Supreme Court Justice Sandra Day O'Conner has brought the issue to more prominence by forgiving her husband with dementia, discovered to be having sex with a woman in the nursing home he is now a resident of.
I heard an interview with Justice O'Connor a couple of years ago in which she basically accepted the fact that her husband didn't know who she was and was having sex with other patients. She seemed rather pragmatic about it.
If they don't spread disease and can't impregnate, perhaps it will keep them calm. Maybe it's just what the doctor ordered, so to speak.