I don't think a majority of people don't care. The causes of obesity and how to un-obese people sustainably and over the long term is still not entirely known.

I don't think a majority of people don't care. The causes of obesity and how to un-obese people sustainably and over the long term is still not entirely known. We can cut someone's stomach to a fraction of its size, and the fat person still regains weight after 10 years. The best weight loss drugs that are being researched are actually hormone-based, not fullness-based or some other signaling. There's something fucky going on with the way obesity occurs that doesn't appear to have much to do with how much a fat person "cares" (and in fact, caring too much in the wrong way actually makes it worse-- internalizing fat shaming narratives tends to fatten people regardless of their weight!). I also think lack of exercise isn't a care thing. The US literally works more hours than other first world countries-- who has the time to hit the gym or go for runs?