One problem with willpower is that it's poorly defined, and poorly definable. How is it measured? Researchers attempt to measure it objectively. One measure is plunging a subject's hand into icewater, the longer they tolerate it, the greater the measure of willpower. But it doesn't really measure willpower, it measures tolerance of ice water. Two people could feel the exact same measure of discomfort, although that's subjective and can't really be measured, in which case maybe the person who stays in the water longer has more willpower but since you can't measure the actual discomfort--the person with the higher tolerance to the ice water might feel less discomfort in the first place. People with depression are said to have a lower tolerance to pain, and given the same painful stimulus, complain that it hurts more. Are they wusses? Or do they actually feel more pain?
Two people could be applying willpower for weight loss, whether it's taking calories head on, or avoiding certain types of calories. Both are fighting an urge to break the diet, if one breaks, and the other doesn't, you can't really say how hard they fought--one may have fought harder, because their drive to break the diet was stronger, but still broke their diet first. Even if you see somebody who doesn't seem to bother--are they showing a lack of willpower? Or has going up against the beast 15, 20 times, only to fall, taught them helplessness? This is a risk of saying it's all genetics, it feeds into this idea of helplessness.
People might need to take responsibility, to do so they're going to need to know that there are some effective responses. And to look for what's personally effective. If something works for you and I try it, and it doesn't work for me, have I failed? Maybe. Maybe it's just too hard for me, and I should try something else. Plenty of people keep a jar of nuts around to have a small handful as the ideal snack now and again, or a jar of peanut butter and eat the odd tablespoon. Won't work for some people, they'll just binge. For the first group, having these snacks around helps them, decreases the amount of willpower necessary to stay on track. I'm in the second group, nuts and peanuts are a challenge instead of a supplement to willpower. In another context they can be helpful even for me--overdoing it on nuts at Christmas, maybe I'll gain weight that day, but I'm still better off than if I gave in to cookies etc. Understanding that my willpower is limited allows me leverage what I do have.
I remember Gary Taubes responding to a question after a talk on Youtube, I don't remember the exact question. But he said that one thing he worries about, if there ever were a paradigm change, and the carbohydrate/insulin hypothesis came to dominate--instead of assuming a general gluttony, people who remained obese might be accused of a more specific carbohydrate gluttony. Jimmy Moore gets accused of this all the time, who knows, it could be true--but I have far less propensity to obesity, clearly, than he does, and I'm quite capable of becoming overweight, if not obese, while eating a very low carb diet. Atkins got me to barely overweight instead of barely obese, it takes a more ketogenic approach to maintain a "normal" bmi. (I know bmi isn't perfect, but the mirror/tape measure/degree or absence of exercise-induced asthma show that it's a reasonable proxy for me as an individual). I can get fairly lean on a higher protein approach with restricted calories, but I'm hungrier and the leaner I get, the more I'll tend to binge. I went most of a decade without any carb cheats, dieted down to 154 and wound up binging on things like honey and maple syrup--things that hadn't even tempted me, for all that time. Switching to ketogenic ratios flipped a switch, it was remarkable. Was it easier to resist cravings? Hard to tell, since cravings stopped.