S/O Elf on the Shelf- Why is the Elf naughty?

TinyPinkBug

Why does the Elf do naughty things at night?  I know not everyone's Elf does, but I just don't get the idea of the Elf doing things like baking cookies and leaving a mess, or getting feathers everywhere?  If they are supposed to be there for good behavior, shouldn't they lead by example and do favors at night or maybe leave tiny presents (like  piece of candy) for good behavior?  I know it is for fun, but it seems to be sending a mixed message when the Elf is naughty.

And has anyone seen the inappropiate Elf contest pictures on some Mom blogs?  I do think those are funny for adults and have enjoyed looking at those.  But I would hate for my or any kids to come across those on a Google search though.