While I am not a therapist, I still am not convinced that this "emotional support animal" business isn't an excuse to bring pets on board without a carrier or fee. But last month I was on a LAX-JFK flight in F where the guy behind me had a little chihuahua and spent the entire flight clutching it to his chest while cooing and talking sweetly to it. At one point, I struck up a conversation with the guy, and he said that the dog flies JFK-LAX-JFK at least twice a month with him, always in F, and has never had any trouble at all.
But.....was the chihuahua a pet or a support animal? The guy was treating it a lot like a pet.