YABVU because you don't have any understanding, but YANBU at the same time. All diets 'work' but they really don't work for everyone all the time. Eat less do more, sounds so SO simple, but its not a case of eating less, but usually, eating more of the right things.
I've struggled with my weight since pre-teenhood, not my mum's fault directly either (unless her obsession for healthy meals was the reason why I'd buy chocolate - which it kinda was sometimes!) yet I am quite nutritionally savvy and have always been active.... I tried every diet going, every eating plan and some worked some of the time but none worked as a lifestyle choice.
Until this year, my 37th on the planet. I've lost 2stone and counting, very happily, easily incorporated into the 'family' and I'm happy and yes, at times think 'shit this is actually EASY!!'.
I also know many people who eat very little and are very very fat. I truly believe its about balance, eating enough, not too little, not too much, of the right things, and its something that is EASY, but involves forming a habit, which takes at least 2 months ancd ongoing reminders to get right.
Illogical to people who've never struggled, but then so is anorexia... yet its a problem, have a heart. Accept that you don't kmnow everything, and that's what is obvious to you maybe more complex for others and you won't come across as an annoying twat with no empathy, even if fundamentally you aren't wrong.
So yeh, YABU... sorry for long post.