This includes myself. I recently put on a bit of weight and I know exactly why: second servings, having a few beers, difficulties sticking to a diet with kids and dietary allergies in the house, no time or too lazy for exercise. It's all on me.
Something that can be fixed by just putting your mind to it shouldn't have to be treated with pills.
For some people it will probably be the hardest thing they ever do - I'm not downplaying this. So, for people who don't have the willpower pills is probably the best solution.