I'll tell you why I like this concept and why Ive recommended it in the past to people.
Most carbs should come pre workout and post workout and maybe post cardio (although thats debatable because of the lingering fat burning effect in which you might want to use that time post cardio)
So with that said.....
When you diet down, you usually do one or two things
high protein, mod carbs, low fats (Aceto way, Farrah way, I believe this is the Magnum way also)
high protein, mod fats, low carbs (Palumbo and others way)
Shelby and John i believe like carb cycling so in a slight resemblance thats more high protein, mod fats, low carbs (although varying)
So whats always the huge problem when someone is dieting? They cheat, they fall off the wagon.....and blow their diet.....but in the offseason if you practice some of these concepts while putting most of your carbs pre and post workout....it can lend to some ingenuity as far as meal planning while dieting down because youve allready practiced it all year long pretty much in your meal combo's.......you now have your staple meals you actually LIKE to eat down pat for when you are dieting (although things might get a little bit more meticulous when dieting obviously).
I also like it in the concept that for some people not as educated or driven as the above people......and really dont know about insulin spikes and glycemic index's etc etc etc.....and just want to follow a simple plan......sometimes simplicity in telling them to eat protein/good fats or protein/clean carbs can be very easy for them to do so they dont do exactly as Gunsmith said above.
There is a huge problem in the concept though as far as people trying to get insanely meticulous in it offseason and eating zero fats or zero carbs in meals and thats when it can backfire somewhat.....but I thought it was worthy for people who dont like to delve below the surface of things to keep them relatively lean in a simple concept.
But again i always tried to relate it as "just a concious effort not a meticulous effort" i.e. lean red meat and brown rice pro carb meal even though the red meat has fats in it.