There is a popular saying in my country that says "Taste is not discussed". So if anyone has the urge to get a tractor on your computer screen, I do not see any harm. In fact sometimes we downloaded some pictures not for wallpaper, for use in school work, college and even in business portfolios
Well, but there's going to be a farmer, or an agricultural engineer who's done with his profession, loves what he does, and even in front of his PC he does not want to lose contact with his roots. There may be ... Or simply someone who likes agricultural implements, there are much more peculiar tastes than this :D