If the 'big secret' is hard work and de la maza makes a high standard and a person wont do it or afford to do it then there's nothing wrong with its approach at chess no matter what you tell them they wont do it. So, if chess is alive and has infinite possibilities and everyone has the ability to reap its rewards then how does a person do as little as possible without making any sacrifices without making a goal or just doing nothing to improve? Say if you even have a perfect memory?
I think that strategy demands learning on the spot, or pre arranged knowledge that allows for easy access. And strategy depends largely on what opening you play. Usually, during OTB play demands quick play and decisions, and lets be honest this is the 21st century information is found and used. All of my strategy books are found but not used. My tactics books however are found and used in everygame. Tactics are concrete while its takes wise thinking to make a tranference between bishop vs. knight trade.
I like that comparison of 'snake oil'. But i think the real question is: does the system make the man or the man make the system?
The book does succeed in driving that point (hard work) home, but where it fails is in being organized in a way that facilitates learning.