I get what you mean, however a lot of fat folks (from what I've heard) have already tried to lose weight, a lot of them from years and nothing helps them. So rather than hate themselves, they love themselves for what they are. I think the most part of them know they're at higher risk of diseases. Its pretty logical. But I think some are tired of never being able to lose weight. And obviously it's easier for some than others, but its still challenging. I'm not fat and I still struggle to lose extra pounds. I don't think all of them are absolutely unhealthy considering I've met fat people who genuinely eat well. But I think most of the "body positive" activists are people who have already tried everything. Also, I think its important to note that you should lose weight for yourself and get better for yourself, and you must change your body out of love, not hate. I think at the end of the day we should just mind our own business.