You're genetically programmed to protect children. Doctors and hospitals know this and exploit it. Unfortunately children with cancer or birth defects are money sinkholes.

Spartan parents would kill children with defects. In contrast we keep physically and genetically damaged children alive (or on life-support in the case of cancer) at much cost to ourselves and at peril to our offspring. Would you want your daughter to marry a man who carried a life-threatening gene? Did she? That's what we're doing. Maybe someday we'll be able to fix these problems, but today we cannot.