No, they are in fact 'soft horror'. Let's look at the evidence.
Ring a ring o roses - this is not a sweet collection of nonsense works strung together for the purpose of dancing and falling over. No, this is a song about the Black Death which wiped out huge swathes of the European population in the Middle Ages. The ring being the red rash, the pocket of posies are the herbs that were carried to ward off germs (not terribly successfully), the sneezing a further symptom and the falling down... well I think you can figure that out for yourselves.
Let's look at some more.
Rock a bye baby. In this rhyme some idiot has placed the baby's cradle in a tree from which it promptly falls out and down comes baby cradle and all. I'd rather not think about the consequences of these actions.
Jack and Jill. Jack 'breaks his crown'. Sounds to me like he fractures his skull. The boy needs hospitalisation and stitches. What does he get? Vinegar and brown paper - yes, that well known cure for a bleed on the brain. Jill comes tumblin after, but we don't get to hear what happens to the poor lass. Presumably Jack just left her there while he messed about with home remedies.
Little Miss Muffet - not only does she have to eat curdled milk, but she gets her wits scared out of her by a giant spider.
The old woman who lived in a shoe - will someone please call child protection.
Three blind mice - no one can pretend that this story ends well for the poor mice.
You get my drift...
And now, for my entry to the Inspiration Avenue creative challenge entitled Nursery Rhymes from which this strange blog post cometh
Watch them go round that bush... for tis not the Mulberry Sale right now and verily are there only four handbags left, but 6 little ladies dancing round the tree...?
Original illustration by Arthur Rackham, Mulberry Handbags borrowed from Mulberry (hope they don't mind, but I did give them a link...)