I understand. No need to be sorry. It might not be something that people hear about or speak about a lot, but it's actually become increasingly common in recent years. To a large extent, this is due to drug abuse and it's preferable to have grandparents raise and/or adopt their grandchildren than to see them go to foster care.
Also, in the past couple of decades, kids have been having sex at ridiculously early ages and then there's a child in the mix, with children for parents.
There are lots of reasons that these adoptions happen. We were lucky - and Jacob, too - in that it happened right after his birth. Some kids get dragged through several years of hell with unstable teen mums and they see things no little kids should see.
Anyway - I'm not trying to convince you. Just trying to help you understand. I appreciate your opinion. People won't always agree on everything, and that's okay.