This was a popular play, back in the day, back in 1934 to be exact.
One truth still holds for sure. People readily panic over how children are being treated at school. Consider the great Satanic Panic of the mid-80's, when nursery school owners were charged with doing horrible things to schoolchildren, based upon no physical evidence. The whole thing was based on the testimony of children who had been suggestively questioned by therapists who effectively persuaded the children to believe things that simply were not so.
I imagine this is all about the helplessness of children, who cannot look out for themselves.
But it's also about fear overriding critical reasoning.
Rhyme of the day:
While I read the liar's play
I fear that fear is here to stay.