Mellissa, you only know of one part of the ‘fat acceptance’ movement. You seem to think ‘fat acceptance’ is “don’t hate on, mock, or deride fat people”.
Sadly, ‘fat acceptance’ has developed into something else, something completely f’ing insane. They encourage people to believe that medical science about obesity is a conspiracy of big pharma. They encourage people to believe crazy, self destructive things like “some people are just unable to lose weight”. They encourage people to see obese people not just as humans worthy of love, but also to see obesity as being more desirable than being healthy.
I admit there are awful people out there that are opposed to fat acceptance because they are full of hate and judgement of overweight people. One (or more?) of them even commented on the parent post. But there are also people skeptical of, critical of, or opposed to ‘fat acceptance’ because we’ve seen that portion of the movement which is outright harmful to society.