Consider middle/high school Spanish classes. There are a diverse mix of people in them and they are taught by a diverse range of people with all sorts of colorful textbooks and methods. Do most students come away from those classes with any long-lasting appreciation for Spanish? Do they retain any useful information? In my experience, most people took it because a foreign language was required, and promptly forgot all but the basic tourist phrases once they got to college.

Basically, I think we shouldn't be setting our sights too high with regards to programming education. It certainly is possible for everyone to learn, just like every other language. But life is short, and it isn't reasonable to expect everyone to be interested in speaking math to computers, just like it isn't reasonable to expect everyone to be interested in speaking Spanish to people.