I feel like the fat acceptance movement has two purposes based on what outrages them.

First is the anger that other people might not find them attractive. I'm assuming a lot of these people derive their self-worth from the attention of others. Yes there are fat people out there who are happy with who they are, but a lot of the comments I see are about how so and so doesn't find them attractive and how that makes them fatphobic, or how they have sex with all these fit and attractive men as if that validates their existence. There seems to be this whole fat woman/fit man narrative going on with the whole movement and it actually strikes me as vaguely sexist, to be honest. I rarely see any male fat activists in the first place, let alone fat women praising the bodies of fat men.

The other is that other people get upset when they encroach on their personal space, or require them to pay more for the extra materials their specialised items cost. These things point to how their weight is genuinely becoming a liability to those around them, and rather than accept that as the consequence of their lifestyle, they are angered that society doesn't bow to their whims and cry out discrimination. If your top costs 20~30% more in materials, then it will cost 20~30% more for you to purchase it. If you are so big that you require two seats to sit comfortably and not upset everyone around you, then purchase two seats. It's the price you have chosen to pay to maintain your weight.

But most of these fat activists will never truly be at peace or happy with themselves. They subscribe to a movement dedicated to victimhood and pointing fingers. Why bother loving your body and doing the best you can to care for it when you can sit on your mobility scooter and drive around calling every slim person you see a cunt. It's a lot easier than actually caring for yourself.