Simple, parents come back because they love their kids. So the parents should be allowed back into the life of the love ones they use to live wish. Or else everyday they will fell bad for themselves or wont be happy. That could lead to drinking. Smoking, other drugs even suicide. The father or mother feels as though they are not being accepted and acceptance is really important. Depending upon what the parent came from, whether it was rehab, hospital, maybe even jail, they should be given a chance only if they get through authority and authority believe it should be allowed or just.
It is Impeccable! Knowing parents would come back for their kids when they put them up for adoption. Because once you put them up for adoption that means that you don't want them or don't have time for them. If their parents came back for them that would mean they love their children more than anything and obviously can't live without them. And want them back, They obviously thought about their decision.
The only bad part is what about the kids? The kids might be all grown up at least like 7-8 years of age, and their parents come back and they are going to keep asking their parents why they weren't with them in the first place how are you going to explain to them that you basically gave your kids to some other family that doesn't belong to them.
If you want the child, then you don't give up parental rights. You tough it out and you keep the child. Parenting is about convenience, or being easy. You are either up for it, from Day #1, or you are not.
If you give up the child, then you should have the decency to stick to that decision. It is only confusing to re-enter a child's life and upset the stability he/she has with the adoptive parents. It is also extremely selfish.
When the child is grown, then making contact is less traumatic & easier to understand. At that point, it becomes an acceptable move.
If a parent gave their child up for adoption, they are also giving up their parental rights and responsibilities. Even though the child may genetically be theirs, it isn't in legal terms. So legaly, the child isnt theirs. It would also be traumatic for a child to meet their genetic parents at a young age.