I think the vast majority of landlords are parasites, but definitely not all.

You think every single person should be entitled to hundreds of thousands of dollars of property on loan? Some grown ass adults out there struggle to tie their shoelaces because they're still holding their crack pipe. Landlords are the vehicle by which the needy gain access to housing in capitalism, they're a symptom and not a disease. Fix capitalism (with socialism) and the symptom will disappear.