You are so full of it. Willfully ignorant of the majority of caring pet owners never having a problem keeping the unit clean, free of pet damage.

Cats are the easiest, litter box is all the require. Modern urine residue control spray/treatments remove the smell quickly. There is no years of smell.

You also fail to mention the majority of damage comes from the renters, not the pets. 

Good to see you know your limitations. Clearly not qualified to be a pet owner, or a parent of children. You just don't get it. An angry person all their life. Sad.