It makes the houses look newer, cuts down on allergies and I can typically rent the houses both faster and for a higher rate. 

Tenants complain about allergies, pet dander, etc., plus carpet gets filthy and has to be replaced frequently.

Tenants have rights, and for those with severe allergies who decide to rent in a pet-free building because of those allergies, those rights include the right to live in space where their allergies are not triggered.

I'm under the weather RightNow but blame allergies.

Not every buyer will want one but some with allergies or needing cleaner air it will be a selling feature.

Unfortunately, he used the entire carpet as his personal bathroom, had the tenant complaining to me about mold smells giving her allergies (nope - $600 worth of testing proved that), and drenched the entire subfloor in a terrible smell.

Turns out they smoked in my house (against the rules) snuck a dog into my house (against my rules because one of my kids has allergies), then they looked right at my ring camera and said "I know you are watching" and then threw their cigarette butt out on the ground.  

My standard response with a smile: "Some other property"2) We (or my kid) has allergies, would you mind ripping up the carpet and replacing it with hardwood floors?

Our 4month old baby also has food protein allergies and requires an expensive diet.