tl;dr: Don't take security advice from organizations whose job is spying on you.
I don't know about anyone else. But the NSA is one of the last organizations I'd let give me security advice. I wouldn't put it past them to purposefully omit a pointer or two in the hope that those who follow the guide to the letter not knowing any better will leave a way in. Based on the other comments the advice is banal rubbish. Perhaps this is purposeful.