Your idea is not wrong, but it is also important to give consideration to the welfare of this children right after they are taken away from their parents custody. The family is the foundation of every human community, and if one is deprived the right of belonging to a family, then there's no saying what could become of that child in the nearest future.
Furthermore, parents who have certain setbacks or faults can be temporarily placed under a consistent correction scheme. In other words, these children do not leave the custody of their parents and the parents involved get the proper and more permanent solution to their inadequacies.

Ponder on this fact too.