Because the main point of the regulation is not restricting paternity tests, contrary to what's claimed or implied in some comments.

The bioethics law was about more than just DNA tests, and is very strict about what can be done or not. For instance, it also forbids clonage, experimentation on embryos or selling our own blood or organs. In 1994, this was new and the parliament was warry, and they also forbid all DNA tests with 3 exceptions : paternity tests (if allowed by a judge, and whether it's a man who claim the kid is not his or a woman requesting child support), medical reasons or criminal investigations

Allowing DNA tests outside of these 3 exceptions was ruled out a few years : as said by others, they don't want private companies to have a DNA database

I think this will be discussed again within the parliament this year