When I am dictator I'll ban all fizzy drinks, the amount that people pour down their throats is ridiculous and the lack of understanding that 0 calories with sweetener are fine. (I may allow prosecco to slip through though)
Actually here in lies a lot of the problem - your sin is bad and must be banned. My sin is just a little treat and I'm able to deal with it in moderation. (If we are banning things, all alcohol should go before sugar free fizzy drinks with unproven claims of 'serious damage' from sweeteners, compared to the very well proven and generally agreed damage caused by even the most expensive wine)
No amounts of diet changes will make us immortal. You will get old, ill and die of something. Some people don't think it's worth trading off a life without treats and joy for an extra decade. It's rather patronising to assume that it's stupidity that leads people to make different choices to you.
Go on the slimming threads on here, very very few people are losing weight because they are worried about their health, desire to look 'better' is a much bigger motivator.
For most people, cake, chocolate, sweet foods give pleasure to eat. Carby foods are lovely. (Warm tiger bread dipped in balsamic vinegar is delicious, add some fresh basil leaves and you have the food of the gods.) For many people, that's the only form of happiness they can ensure they will have. Some parents can't afford many treats or experiences for their DCs, but can give them a chocolate bar or a yummy cake to add a nice moment to an otherwise miserable day.
Salad and cake are only comparable for a someone who doesn't understand joy. In order to be thin I live my life in a state of slightly miserable self denial, I can completely understand that others decide it's not worth it and continue to eat the way I would love to if there was any way to do that and still have a small bottom.
This thread feels all terribly judgemental of those who are 'weaker' than some of you. If you are relatively rich, not stressed and relatively healthy, then it is a lot easier to decide to remove one of the many areas of joy from your life (sweet foods).