I realize the point, I think it's the wrong way to lose weight (and I say this as someone who lost considerable weight and has kept it off for more than ten years).
Counting calories temporarily tells someone how much he is overeating, but the problem is the amount he eats is an ingrained habit. Habits die hard, eating less for a couple months doesn't change anything for most people. There is a lot of evidence that most people who diet put the weight back on because they took temporary measures to lose weight instead of making deep lifestyle changes. [Anecdotal evidence alert]: making deep lifestyle changes was one of the hardest things I've ever had to do, and I believe counting calories would have distracted me from that goal.
One can't address a problem until one is aware of it; counting calories is a technique useful for creating that awareness. It's not a diet plan, it's an awareness technique.
Counting calories temporarily tells someone how much he is overeating, but the problem is the amount he eats is an ingrained habit. Habits die hard, eating less for a couple months doesn't change anything for most people. There is a lot of evidence that most people who diet put the weight back on because they took temporary measures to lose weight instead of making deep lifestyle changes. [Anecdotal evidence alert]: making deep lifestyle changes was one of the hardest things I've ever had to do, and I believe counting calories would have distracted me from that goal.