Why dont you call a wallpaper a screen paper ?

the term "wallpaper" has been widely used long before the computer were invented, to describe something to cover or decorate the wall of house, office, building, etc. so when it comes to computer desktop, the term "wallpaper" were used so that users can easily understand that it is used for decorating the desktop background. however this term "wallpaper" only being used in Windows because in Mac it's called "desktop picture". so if you really can't get used to the term "wallpaper", you can consider using Mac. LOL!

It is an interesting question. It is a term little related with the english logic, but indicating how the IT guys' think. Earlier they had used the term firewall, so maybe wall has a print in their mind. I don't know which is earlier, firewall or wall paper. Anyway, both using concrete traditional expression to express technology. If screen paper is used, somewhat strange, as mixture of the new tech with tradition. That is only my impression.

it does function like a wall paper. and your idea of a screen paper is not perfect itself.. yes, the monitor is a screen and it can be screen but it is not a paper to begin with! it is called a wallpaper because it is what its purpose is, to cover your screen with your desired design similar to how a wall paper covers the wall in our homes.