To be fair, it is incredibly rare for anyone to ever be taught how to think. One wouldn't expect a random person on the street to be able to construct a pocket watch, so why should one expect a random person on the street to be capable of critical thought? When people (not just Americans) think of education, they thing of facts and route memorization. They think of equations, historical events, and literary themes. Which is to say, they think of tools and not processes.
It is not just a failure of schools but a failure of parents and society. The education system doesn't teach children how to think, society glorifies individuals who don't think, and parents sit idly by while the brain of their child remains limp and fat. It is only that rare individual who is capable of teaching him- or herself how to think.
How does one do that? Reading can help (fiction vs. non-fiction is a red herring), but learning the thoughts of great men and women won’t allow one to think one's own great thoughts. Rather, it is through discussion and debate that one learns these skills.
Yes, such a debate can be painfully bad, but these are labor pains. There will be stillbirths, certainly, but it is from these painfully bad sham-debates that actual, thinking humans are born.
"There is no teacher but the enemy." It is only by testing one's assumptions, however inelegant that test may be, that the assumptions can be broken and the person be let out.
That is the stuff you want to promote.