Because most nursery rhymes aren't nursery rhymes. They were written as political rhymes, and when they were originally written they were intended as, and read as, biting social and political commentary. read more
Nursery rhymes are meant to teach or show young children that there are consequences to actions. Kids (and adults too!) don't"get it" when we"instruct" them about potential dangers, so we have to think outside the box a bit. In this way, the nursery rhymes become like maxims or proverbs. read more