It was our Rabbonim who issued this decree. We don’t question their reasoning, because, we have Amunat Chachamim. What they say goes. They had the forsight to see things in the long term, as a protection to keep Kedushat Yisrael and it has worked, is it 100% effective? no because, there will always be indivduals who will do what they want anyway, but that happens in ALL aspects of Judaism. But in the majority of cases, it has helped to protect the insincere conversions and all the problems that can occur, especially with regards to the children.
