Losing weight is different from quitting smoking. In the case of smoking, there is no room to justify or rationalize. The negative consequences of smoking always far outweight the benefits. For anyone who smokes, quitting is absolutely the best thing to do.
But losing weight...that's a different matter. It's a personal matter, an individual matter, and it is not always so clear cut.
Certainly, if your weight is negatively affecting your health, that is clear cut. But how bad do you need to feel physically before losing weight becomes a must? Many of us carry around 10, 20, 30 extra pounds and we just live with it, maybe thinking it's not so bad, and the idea of dieting is worse. In some cases it's true.
With weight, it is really up to you. Maybe your doctor can tell you lose weight or else, but other than that it is your decision to make.
There's no doubt that losing weight requires energy, commitment, even courage. But you are the only one who knows if it's an important thing for you to do, and you are the only one who can do it. No one can do it for you.