There is a tendency to dehumanize kids that commit crimes. The system is focused on punishment, not on rehabilitation. These kids are the most misunderstood and most cruelly treated.
Kids with Down syndrome are, by and large, quite affectionate and relatively guileless, and frequently, the attachments to them grow and deepen. And the meaning that parents find in it grows and deepens.
I'm attached to my children with whatever flaws they have, and if some glorious angel broke through the living room ceiling and offered to exchange them for other, better children, I'd cling to my kids and pray away this specter.