Okay I have heard this remark more then a thousand times and it seems to me that if this were true it would make it more convenient then ever to have and raise children.
1) Child care - Worried about leaving little Johnny or Susie home alone. Worry no more, crate them. Yes leaving them locked in their own little, let's call it a playpen, while off to work you go. Also this cuts down on diapers as it should work with kids to help potty train them faster. Just remember to get them to the bathroom when you get home. Oh and let's leave some water for them also.
2) Health care cost - another worry that is a thing of the past. If the cost of the actual care needed seems a little pricey for your budget, ask the doctor how much it would cost to just put them down. A little drastic I know, but still an option.
3) Worried about them running off from your yard while playing outside. Worry no more, the invisible fence will deliver a small electrical shock via their collars to let them know when they have gone to far. Much better and less noticeable then chaining them up in the back yard.
4) Once they are a little older and potty trained, Mom and Dad can go out for a night on the town, by locking them inside the house with a bowl of water and maybe a treat or two.
5) All those immunization records would be marked on the "children" tags that they can wear around their neck or wrists.
6) Missing and lost. Don't worry just like our pure breed dog a chip will help them be returned home when found.
I mean lets face it how often has a co-worker told you that their pet is just like a child and is another member of the family. So if that is true you have to worry about how they actually would treat a child if they ever breed.