mati:
Now I'm curious what would happen if the title is: "The girl who never went to school".
I don't know what the reaction would be but I'm certain what the plot would involve: Visits from the truancy officer for spankings.
jbeverley is right about the reasons for finding the school scenario attractive, to which I would add that the setting has fundamental to it an imbalance of power. This in a genre where submission is an important facet makes the setting not just believeable but even reminiscent for those of us old enough to have experienced cp at school.
The submission to school authority is expected, and so when this involves bending over there's no way of escape which adds to the titillation value.