Why Do They Do That?

This seems incredible to me, but there are some people who actually put their feet up on sofas, couches and armchairs without removing their shoes. I understand that not everybody has realised the sense in always removing their shoes at the door, but putting shoes on sofas is just bizarre.

I even remove my slippers before putting my feet up on the sofa. My parents do too.

Do they think about the fact that somebody is going to sit where their shoes have been positioned?

Do they just love their shoes so much they will not even remove them to put their feet up? Do they even wear their shoes in bed?