All applicable warning flags and disclaimers, I'm not a psychiatrist or a sociologist or an anything-ist, I've just lived through some interesting times, this opinion is strictly that of the opinionholder and does not reflect the viewpoint of anyone but them, et cetera et cetera et cetera . . .
You wanna know what the *real* force against Size Acceptance is?
A lot of people have hitched significant portions of their self-esteem to their image. Thin is both desireable and attainable, or so the culture says. People who are thin can therefore take pride and pleasure in that fact, and they reap all kinds of little rewards from an approving culture.
Now here come these upstarts who don't fit the standard, whom the culture judges as dirty and unworthy. These upstarts, these . . . these . . . *fat* people, suggest that body size isn't a sign of rigorous self care, adversity overcame, or the love of an approving God. That body size is as meaningless as having blue eyes and blond hair; attractive to many, symbolic of nothing.
That a keystone of your good and approving feelings about yourself and people you admire are a house of cards built on a Jello foundation.
That maybe you're not so awesome after all, because how else is awesomeness defined than by comparison to the *un*awesome? Can't have winners without a whole lot of losers.
That maybe exercise enthusiasts aren't entitled to more respect than any dedicated hobbyist -- I knit, but that doesn't give me the right to call all non-knitters unartistic time-squandering wastes of blood and organs.
It isn't that slender people have a fundamental character defect making them bigoted jackasses. It's that people aren't even aware of the little ways the world favors people for things that have nothing to do with their sterling qualities as people, and that, whether we're aware of it or not, we're all actively participating in someone else's oppression
That's a nastybitter pill to swallow. And in this era of political correctness overcorrection (another time, dears), no one likes to seem like they're too sensitive.