I've seen a lot of people take a bit of a snobby attitude about wallpaper making -- that it is somehow "easier" to make wallpapers than skins.

While I agree it is less time consuming to make a wallpaper than a skin. The artistic merit of wallpaper making is no different than any other form of art creation IMO.

Rather, making a wallpaper is a good way of getting a snapshot of the artistic talent.  Making a good wallpaper requires both artistic talent in creation and a good eye for usability. Clearly, most people (including myself) lack either one or both of these qualities.

So while almost anyone can make a wallpaper. Very few people can make good wallpapers. 

In my view, the time to make something doesn't reflect the talent involved. It just involves the amount of overall effort.