If you don't stick to using their products you just slip back into the bad habits and the weight goes back on, that's how they make their money. They never educate people to eat properly, that's the last thing they want to happen.
True enough. Weight loss isn't hard, but the diet industry want you to think it is. Whenever I want to lose weight I simply stay in calorie deficit most days of the week. Eating around 2,000 cals a day. The weight steadily falls off. No need for special diets. Just rein in the shite food and eating to calorie excess.
The will power bit at the start is the difficult bit. Get past that and anyone can lose excess weight without going on a 'diet'. Of course, the diet industry doesn't want anyone to know that.
Simple maths tells us that if we eat fewer calories than we burn each day we will lose weight. It's like a bank balance. If we spend more each day than we put in, our bank balance goes down. Save more than we spend, and the balance goes up. With food, lower calorie stuff means you can actually eat more food and still have room for treats.