What do you think that was in response to?

Half the country being fat and not wanting to take responsibility?

Right. Fat acceptance was created in response to the sentiment that you're expressing - that it is a moral failing (responsibility).

Taking responsibility for the tremendous surge in highly-calorific, ultra-processed food over the last forty years or so?

And these calories are in the water supply? No, the fat people choose to buy and eat that food. I'm on a 700C deficit right now, it's not very fun, but it works because I have the discipline to not order a pizza.

It can be, but so can existing as an ordinary citizen and not devoting your life to activism, abstaining from everything but the most sustainable resources. Some people lose or maintain weight with zero effort, while some have significantly lower TDEEs and experience actual Minnesota-starvation effects, so I disagree. At least make the moral failing not doing the basics, like planned meals with whole foods and some amount of exercise, so it’s fair.

Anyways regardless, morality is irrelevant here. The rest of society would be better off if these people lost weight, and I doubt forcing them would go well, but voluntary GLPs would.