It is simply misguided:

“No such program of eugenics could work: there is no lasting agreement about desirable mental or physical qualities; an individual’s worth depends on other, incalculable ingredients. Environmental conditions mingle with inherited characteristics to make us the way we are.” - Out of Our Minds, Felipe Fernandez-Armesto

Like “human rights” and “education”, it is much easier to be for “desirable qualities” than to say what they are.