Nicolaides' starts with his famous statement "THE SOONER YOU MAKE YOUR FIRST FIVE THOUSAND MISTAKES THE SOONER YOU WILL BE ABLE TO CORRECT THEM." Most students will indeed spend a lifetime at this. Well at least it tells were N's method will get you.
Imagine a math teacher telling you to figure out arithmetic on your own and then assuring you that after 5000 adding mistakes you'll surely be able to correct them. Is that what a student should expect from school?
Along with the usual double talk that sounds serious until you analyze it, the book is full of silly suggestions and vestigial anecdotes. It also contains idiotic schedules designed to lead the student to imagine he is making progress. I have to laugh at these. It is like a music teacher who doesn't know the scales giving you a long schedule, which starts with you figuring out how to play Jingle Bells and infers that you will eventually figure out Mozart.
I suggest a look at page 34 and the illustration called bulk. It shows that the author knows nothing about drawing form and is an advocate of modern art school sloppiness. I love page 43 as a perfect example of Art school Garbage-can-ism. Page 79 shows watercolor as bad as can be. For utter stupidity check out pages 200-202.
Well at least N allows you to compare the ignorant student output with classical examples like Michelangelo and Bruegel etc. This should get any student who has any brains to consider that there is lots that he doesn't know.
The book in spite of its claims conveys no knowledge of: the geometry of line, light and shade, perspective, how to draw solids or technique. It does give good examples of how badly most art students have been taught to draw for the past fifty years.
The Natural Way to Draw essentially conveys a theory of learn by doing, but doing so without knowledge. It is well illustrated with obvious results.