The point the author is trying to make is that we should have provide more programming classes in high school, which people have started pushing for... but the

The point the author is trying to make is that we should have provide more programming classes in high school, which people have started pushing for... but the problem is there are not as many high school teachers qualified to teach AP computer science as there are for humanities. If they are qualified they can probably earn more working in software than through teaching.