Like most left-wing discourses, anti-ableism started with the reasonable and necessary attempt to counter-act the discrimination and mistreatment of people with disabilities.
And it kind of snowballed into "actually, being disabled is awesome and you're a nazi fascist if you want your baby to be healthy". And so they started branding women who don't want to/can't dedicate their lives to caring for severely disabled children as Hitler.
So it's cool to yeet a perfectly healthy fetus for any reason but if you abort primarly because the fetus will be a severely disabled child- youre scum. So they want women to have disabled and diseased babies to virtue signal ideological purity.
This ride from sane and useful anti discrimination ideas- to absolutely deranged, useless, perversion of basic common sense- can be seen everywhere in leftists movements, unfortunately.