Why Can't Programmers Read?

Two days ago Jeff Atwood wrote a post entitled Why Can’t Programmers.. Program? about the level of candidates in job interviews.
He gave an example of a very simple "Fizz Buzz" test given by Reginald Braithwaite, meant to rule out people without the bare minimum of programming skill.

As it turns out, developers who read weblogs stop reading once they reach any kind of "test", since many people took this trivial task as a challenge, and at this point there are 105 comments, most of them with "solutions" to the test.
Jeff wrote a second post trying to explain his original point, telling people WHY that test was needed and that solving it proves nothing, and Phil Haack wrote a post entitled "Why Can't Programmers... Read?" mocking the people who answered Jeff's original post.

As it turns out, there are still people out there with reading difficulties, as I was amazed to find someone actually wrote a PHP code in a comment to Phil's post!
Someone like that is worse than a developer that can't code, since you can teach a person to code, but how can you deal with someone who ignores what you are saying (or writing)?