What does Harper Lee seem to be saying about "modern" education?
Harper Lee is unkind to "modern educators" who are all theory no brains. The school teacher is ignorant, yet not intelligent enough to know it. Hence, she tries to "reverse the damage" done to Scout by her father, who taught her to read (incorrectly) by ordering her not to read anymore. The innocence of the teacher is revealed in her bumbling attempts to control her students' learning--not by building on what they already know, but by shaming them and trying to force them to revert to a step that they have long since passed.
This is a system without intelligence. It is a system that asks for obedience without possing sufficient authority to command it. It asks students to follow the rules without acknowledging that the rules don't matter. Worst of all, it is a system run by well meaning but inefectual reachers who have no real understanding of the cultural climate they work within.
When Scout tries to explain the origins of her name, Miss Carolin responds: "Let's not let our imaginations run away with us dear. Now you tell your father not to teach you any more...You tell him I'll take over from here and try to undo the damage...Your father does not know how to teach. You can have a seat now."
I mumbled that I was sorry and retired mediatating upon my cirme. I never deliberately learned how to read, but somehow I had been wallowing illicitly in the daily papers."