That's because this campaign is about changing that very law. Saying that "this is blatantly illegal" misses the basic point of this proposal being a CHANGE of the law that makes that illegal.
No, it's even worse. This is an attempt to bypass those laws by bringing in a new one at European level, and having that supersede the obnoxious protections in member states' Constitutions (Germany is hardly the only one with such protections).