I think Faz explained my opinion better than I did: I think there are more important ideas in the fitness industry to challenge than this and you could gain more by doing so. Could you train with just a barbell? Of course you could. I have read books on the training of guys like Sandow who didn't bench press and didn't have squat racks and they got strong as hell in what they did do. For your average gym rat though challenging things like rep ranges, ie: you can't get bigger whilst doing low reps, or diet: you can't bulk without 50% of your diet being carbohydrate.