Because his eating pattern is a myth and offers no benefit over just counting calories.
Yes he does and here's why: losing weight, and this is what most people are concerned with and what I am talking about when referring to IF, is one of those things that are simple but not easy. Simple because all you have to do is be at a caloric deficit. It's not easy because you have to be at a caloric deficit. I competed in different weight classes during my Jiu-Jitsu competition days. So sometimes I had to gain weight and sometimes I had to lose weight. When dieting to lose weight I got hungry simply because I was eating less than I was use to. Now, I always ate breakfast even though I am never hungry in the morning because that's what you are suppose to do. I was always taught that breakfast was the most important meal of the day.
Now when I skip breakfast I really don't get hungry until well into the late afternoon/early evening. I go around 16 hours without eating and therefore find it easy to eat just two meals a day without those hunger pangs and cravings. And because I am now cutting the number of meals I usually have in half I can eat more in those two meals and still be at a caloric deficit. I think that by eating breakfast you reset your body back into eating mode and get hungry every 4 hours or so. I mean, you never get hungry while sleeping even if it's 8-9 hours because you are not in eating mode. With IF you extend that window.
IF just makes cutting calories so much easier. Like I said before, I just did it out of convenience but found that I was just losing too much weight and getting really skinny so I still force down that breakfast though I make a smoothie since it's fast and easier to force down in the morning instead of sitting down and eating.