"The Red Pony" and "The Pearl", by John Steinbeck, are poor examples of good literature and should not be taught in schools - while it would be unjust to describe Steinbeck as a poor writer, these two examples of his work both undervalue his writing talent and provide a rather lacking template for students who may want to write fiction of their own.
Both books show minimal charachter development, leading to characters that readers have difficulty sympathizing with, which in turn leads to a less emotionally potent story (as most fiction writers and readers know, it is often the potency or depth of the story that draws people in.)
"The Pearl", especially, is a weakly-plotted story that does little to hide its patronizing center point - a childish lesson to "be careful what you wish for".