I think what he was trying to say with that statement is that taking every set to failure will lead to burn out and missed workouts.
Bill Pearl stated the same thing but he was direct to the point. He said don't train to failure. I interpret that is if your doing volume and your first bicep exercise is 5 sets of 8 reps only the last or the last two sets should approach failure.
Just think if you wanted to be a good runner. Would every single day in training be an attempt at breaking a personal record? That would be insanity yet many weight trainers attempt it.