I don't have ASD but I have ADHD, and based on my experience I think it's extremely fair to see knowingly inflicting upon another living being a disability that causes great pain and suffering throughout their entire life, as fucked up and immoral
It's like pugs and pitbulls, many people can agree in the thought "why are we intentionally creating more canines with terrible disabilities which badly hurt them for the rest of their life?", so why is it so bad when the same logic is applied to humans?
I think it's dumb to describe it as "eugenics", considering that's a term almost entirely associated in the modern day with Nazism, forced imprisonment/torture/forced sterilization of certain groups, and racist beliefs. Wheras this seems concerned with wanting people to not suffer nearly as much after they're born, so they're expressing how they're upset that people chose to create a new life with more suffering than average when there's tons of equally good alternatives, and I think that's pretty different than flat out promoting genocide...
What's wrong with adoption anyways? It's pretty selfish to bring a new life into this world for your own personal satisfaction when you could literally just take a child who's already out there suffering and make them not suffer for no extra loss.
I find it stupid that they describe it as "ruined lives" though. Especially for the parents, like wtf just be a good parent? It's not like most parents have a kid with no difficult challenges to face whatsoever. When you become a parent you sign up to being exposed to any and every possibility that could come from a kid. If you become a parent and then go "woe is me, I didn't expect autism so I can't deal with this, don't blame me for not parenting correctly" then you shouldn't have become a parent. The only way parents can "ruin" their own lives is if they're a shitty parent, which unfortunately a majority of people are...