[skybrian]

I'm not sure calculus is a great example for your argument. How many kids do you think would actually learn calculus on their own? It's something that most kids think is way beyond them and they don't even know what it is (other than a kind of math) until they actually study it in school.

And that's a standard subject taught in high school. I think if instead you look at why kids learn music or art or dance or drama or sports or a foreign language or religion, you'll find that the parents and relatives and friends often (not always) have a lot to do with it. And even with parental support, often the kids decide it's not for them. And that's fine; at least they got the chance.

I don't see computer programming as being all that different; not every kid is going to be into any given activity, but if they're not exposed to it in a way that makes it seem interesting, that's going to drastically reduce the number of kids who even try it. And that exposure is going to vary pretty dramatically depending on where you grew up.