The holy Chazon Ish osb"m said that the Downs people and the autistics are the souls of tzaddikim (high righteous individuals) who come into the world to facilitate our soul correction. They need no soul correction, that's why they lack free choice.
Kindness is a trait - and a soul correction - that many "go-getters" of modern society need to learn. So what if the Downs people and the autistics are different? You're right; but, it's better to be kind than right.