My grandfather is a veteran of the U.S.

Court House - My grandfather is a veteran of the U.S. who is in stage two of Alzheimer's disease. Upon looking at a house for rent, the owner had already questioned what my grandfather did for a living. When we told him, the man seemed to be very interested in my grandparents renting his property. When the man met my grandfather, he looked him up and down. My grandmother told the man he was a veteran suffering from Alzheimer's. After this, the man got very weird and basically told them they were not qualified for his home. How do you base a qualification on one spouse with Alzheimer's?