Perhaps they ought to put a warning label on the bears in that case. I have a dog. I got her from the pound and in five days, she got parvo. In just five days, I was so attached to her, that I risked long-term damage to my credit standing to pay for her vets. I'm sure that people who have real babies would do worse for their children.
People make that decision every day.
If you could imagine killing to feed your child, then you can imagine killing to feed something that you love even more than your own child. Creepy to think about. You're welcome to the idea, I refuse to think about it any more. Sometimes it's the smallest details that make a SF story really work. For example, there is a wonderful bit in Babylon 5 where Delenn tells Sheridan that the Nimbari sleep at an angle because they believe that to sleep flat on one's back is to tempt death.