Schools in the midwest do not focus on "skills associated with living on a farm". Even in agriculture-centric Iowa farm labor is about 8% of the population, the other 92% of people are employed in offices/stores/factories/etc. For comparison, 5% of workers in California are employed as farm laborers for some part of the year.
The schools entire focus is on university preparation (often to a fault, many students would probably be better suited by a more vocational focus). No public school is teaching anyone to read the bible, and to my knowledge private Catholic or other religious schools are no more common in the midwest than in New York or California.
Ignorant stereotypes based on state/region are just as foolish as any other ignorant stereotype.