Ah. Thanks for the clarification. I misread your statement
I'd advocate for that way before I could get on board with making disabled kids permanent kids
As something along the lines of: "abort your disabled kid before you make her a permanent fixture upon this earth." Which, yikes. Clearly your viewpoint is more defensible than that.
Not quite sure how I fall either way. As somebody who spent years caring for adults with disabilities close to the standard set by this article, I can say that assistance in ADL's can be daunting (depending on the size of the adult and how willing they were to go along with it), but not impossible. Then again, I enjoyed the luxury of going home at the end of the day, taking a few days off, then coming back to them with a fresh mindset.
A little to your point, though- it's important to clarify the scope and limits of prenatal diagnostics. Of those available, the most specific tests- amnio, CVS, and increasingly blood tests- can determine the presence of certain disabilities (certain, not all), but can't test for the severity of the disability. So while it's easy to say, "test for x; if x, and if you can't deal with x, then push the red button," practice is muddied by shades of nuance. Also worth noting- amnio itself (and CVS even more so) comes with a distinct risk of fetal demise. So just making that decision in the first place, even if you're in the group at higher risk of gestating a kid with developmental issues, can be fraught. By the time you're 37 and you've already miscarried three times, just biting the bullet and getting an amnio might be a difficult proposition.
I suppose one might just see the positive test and ask: "am I capable of taking care of a child exhibiting the worst incarnation of this disability? If yes, proceed. If no, abort." But then you're playing with probabilities re. how disabled your child might be (dependent on condition, obvs); will your trisomy 21 kid enjoy near-total function and quality of life, or will he be at the way low end of the spectrum?
The other rub is that people often skew towards optimism when anticipating life with a disabled child, and only recognize the true difficulties when the rubber meets the road, long after the decision to abort is in the rearview.
Does this mean we should greenlight fucking with their endocrine function? No, I'm uncomfortable making that determination. I'm equally uncomfortable with the idea of rolling the die after an amnio, though, and basing my family's future (or lack thereof) on a gut feeling. Either way, as KB already said- it's not a decision I ever want to be faced with, and I empathize with folks on either side of the path.