Because the steps in that section keep getting passed around as possible fixes. Some of them are mentioned in this very thread. Sadly, it's been my experience that the fix Apple does suggest doesn't work reliably (works for some, not for others), either.

EDIT: holy crap, as toddn points out above, apparently that section is also to contradict the bad information that is passed around in Apple's own KB articles: http://support.apple.com/kb/HT5538