My dad had a prosthetic leg, and he bristled at some of the polite or accepting ways that people would talk about disability in a way that stuck with me because he explained it. Basically a dislike of "handicapable" or the notion that you "make up for it" in other ways. To paraphrase: "getting my foot cut off in a car accident didn't come with some perk that balanced things out".

I think a lot of the pushback you got came not from a place of rejecting that they could have a bias, but from the topic being broached as a confrontation of bias instead of an explanation of ignorance.
People, like the poster above, who are being conscientious according to their understanding will get indignant or frustrated when that's met with an unmatched response.

Assuming positive intent colors implicit "positive abelism", or other "positive -isms" that I'm personally less knowledgeable about, as unfamiliarity or ignorance rather than callousness or rudeness.
In those cases, the person is very unlikely to disagree or pushback if informed about their blind spot. The key part in their head was "disabled people are just as important", sitting right next to "good people chip in and contribute". So they respond to "disabled people can't always contribute" with "disabled people are important!" phrased as "disabled people can contribute!”.

Addressing it as a bias against disabled people doesn't fit because that part is correct. Need to address it at where the problem is: a misconception about the relationship between human worth, labor and utility.

Okay, that's fine and all, but "brocialism" will never be enough because it depends so strongly on a person's personal connection. It's not "to each accord to their needs" it's "to each according to their connections."

If you don't see how that disproportionally benefits and privileges in-groups then I don't know how much clearer I can break it down for you. A socialist society needs mechanisms in place to take care of those who would be forgotten by "brocialism" alone.

Maybe the system works for autistic people who can grill, but what about autistic people who can spend two hours explaining the history of North Rhine-Westphalia or Star Trek lore or any other special interest? You think someone with a truck will view that as an equivalent exchange?

Mind you, I'm not saying their talents are worthless. I'm telling you my experience as a neurodivergent person that most people view these things as lacking value and will marginalize anyone whose contributions consist exclusively of talents that most people consider worthless.

Assuming every autistic person can grill or contribute something that neurotypical people value as having worth is wrong because it marginalizes those who fall outside of that limited group, and because it reinforces the system and the idea that people need to be able to contribute something deemed valuable before they deserve to receive help.

And if you can't see how that disadvantages the people whose disabilities are the most severe, then I don't know what will get through to you.