It's very hard to turn those feelings off or redirect them, but good for you for attempting to sympathize rather than condemn - that in itself is something to be proud of these days!
Without judgement, I view the whole "body-positivity" movement as a sad, doomed-to-fail attempt to override our naturally evolved instincts by people who've given in to despair. The problem with attempting to "change the narrative" on something that operates on such a fundamental level is that it generates an enormous amount of cogitive dissonance that one will battle to preserve when constantly bombarded by evidence to the contrary. It's very difficult to convince everyone else to play along with one's well-intentioned but absurd wishful thinking, and those attempting to push the "body positive" message are people who don't need more negativity and dismissal than they were already facing before: it's difficult enough putting oneself out there when one doesn't conform to society's expectations, doubling down by trying to convince everyone that up is down doesn't make things any easier.
Giving up hope in today's climate of misinformation regarding diet and exercise is entirely understandable, and I'm hoping that putting out this article will at least be able to open up the conversation a little more. As I said in the article, life is hard enough for everyone these days, we all just need to be as supportive of each other as we can.