yeah! people are just fat and lazy by nature and they are all weak willed!
You do need counseling, that's not a bad thing though

. Haha just playin bud.
Anyway, I quoted that because this is honestly what I think ^^. There are a couple things you have to realize here.
1) The term "diet" is thrown around all too often in incorrect ways and has gotten such a terrible connotation it's unbelievable. A healthy diet is a diet, a fat loss diet is a diet, a bulking diet is STILL a diet. A diet is just what you eat, not a fat loss program. Fat loss is fat loss. Now that that's out of the way...
2) FAT LOSS programs (not diets) do work. Every single stupid program out there will probably work if you follow it. Does that mean it is healthy and will yield sustainable results? Hell no. But the reason why they "don't work" is almost entirely due to compliance. It's just because people can't or don't follow the requirements. Because when it comes down to it, if you eat less you lose. So if you're not losing, you're not doing that (plateau after extended periods and medical conditions excluded).
3) Although these fat loss diets do work, the point is that even if they do, many of them are not set up for long term goals, and that is really the only problem with them. Of course, some aren't healthy, but the majority of the widely known aren't terribly unhealthy. But as stated, you have to set yourself up to maintain a healthy, sustainable lifestyle over years, not weeks. The key thing in that regard is that people follow fads never even understand what they're doing, why they're doing it, why they're eating what they're eating, etc., and then when the diet is over, they're back to being clueless.