The word “fatphobic” would mean I have a fear of fat people, that is simply incorrect. I hate them. Not people specifically but the movement for things like “oh fat is healthy” or “why should we buy two tickets since we take up two seats” because it is simply incorrect. You are teaching children that being morbidly obese is ok when it is not. You are shortening their lifespans just because your ego is too fragile to handle wanting to lose weight.
“homophobic” also implies a fear of gay people but we know that isn’t how its used, that point is just redundant unless you’re unable to make that clarifying distinction that most people can. also, being hateful or abrasive isnt going to get anyone to listen to you-- it will likely drive people in the opposite direction. this isnt the time or place to make these kinds of comments even if it was in good faith, such that it should be unsurprising that people are downvoting you