Yeah but I mean...
My dog gets excited and barks to let me know whenever someone is at the door. It might crush his spirit if he knew he is just a useless pet and his contribution is meaningless.
If nothing else, it signals to people approaching your door that there is a dog they may not want to have to deal with.
If nothing else, it signals to people approaching your door that there is a dog they may not want to have to deal with.