He even discusses his role in p90x in a comment.
Thinking evolves. Is PB the final word in nutrition -- I doubt it as we learn more we adjust.
My name here (Grandma) reflects my philosophy of living more naturally, like our ancestors did. I think the best advice is to eat food in it's most natural state. I see no harm in eating some fruit after a workout, but fruit doesn't naturally come powdered in box that you mix with water. Generally, if it is advertised, don't buy it.
Lastly, for me, the PB is not about 10% body fat and washboard abs (that's how Marks sells the program) for me it is about healthy living so I don't really listen to anyone telling me how to optimize. I just want to live.
It's grandma, but you can call me sir.