“No child should be killed, let alone because of a chance she won't be "perfect."”
No child should, I agree. However I do not consider a brainless fetus as a child till it develops the aforementioned brains. Simple enough? It’s not killing somebody who already exists, it’s preventing a consciousness from ever forming in the first place and you can only kill what already exist, fuckhead.
Now that being said I would gladly abort my own if I knew for a fact they were to suffer from some serious defects, specially on the mental spectrum but any sufficiently heavy defect would do. Not wanting to put more disadvantaged people into a society which is perpetually complicent in disadvantaging them is much more responsible an action than to bring forth more misery into this planet out of a selfish bid for reproduction at all costs.