You wrote:
2) If a family has other children... it *will* diminish the care, upbringing and quality of life of the other children. So it is not just the parent’s sacrifice. Not just money, but time, and opportunities for personal enrichment.
Many brothers and sisters of Down's children see this in quite a different sense. They might rewrite it thus:
2) If a family has other children... it can increase their capacity for compassion, and an appreciation of simple humanity. Seeing their parents make sacrifices for their "different" sibling will give them the priceless life-experience of knowing what real love is. When they are drawn into being involved in care, they will learn to be caring people. When they see their parents deal with difficulty, they will learn courage.So it can enrich the "normal" siblings, not with money, but with opportunities for interpersonal depth based on the daily, up-close, hands-on experience of generosity, empathy, patience and hope.
You wrote:
4) But this cannot be determined prior to birth.
I would say this applies to all of life. You do not know if the person you chose to marry will develop a gradual neuro-degenerative disease and you will have to give greater and greater degrees of care to him or her for decades. You do not know if YOU will BE that declining spouse.
You don't know how much care your parents or your spouse's parents will need. You don't know if your great, highly-rewarding, creative important job will cease to exist, dry up and blow away. You don't know if a fire will consume your home and all that you own.
You don't really know what lurks around the corner at the next intersection: and life is full of intersections.
And do you know your purpose in life? Maybe you think your purpose in life is to be healthy, financially secure and have enriching experiences with your attractive wife and two orthodontically perfect and accomplished kids; when actually in God's eyes, your purpose in life is to learn humanity from a child with a misshapen mouth who will never stop drooling.
In an Almighty, Sovereign and Infinite God's eyes, perhaps you are a drooler--- a drooler He loves.
My point was *solely* that a blanket solution for a very complicated situation almost never works. Many people will choose a simple solution to a complex problem, and they don’t care how many are injured or killed trying to conform to their simple solution. They do this because more complicated, even individualized answers make their head hurt. Too much thinking, not enough knee-jerk feeling.
Please don’t be like that. This is a situation involving children, and their parents, and their families as a whole. Their lives, all of them, cannot be solved by an armchair ponderer who doesn’t even know them, just the idea he thinks they represent.
All of them, and all at once, as a faceless group, all with the same problem. At least as far as you are concerned.