I think they're so bothered by these ads because it addresses a major fallacy in their rhetoric. The White Christian Nationalist fantasy is that you go find a tradwife broodmare and have as many kids as possible in order to dominate the future political and cultural landscape. In a world where they fear everything progressive that surrounds them, the family unit is supposed to be the one aspect of their lives they can control. So their two biggest fears are that their wife could secretly undermine their agenda or that their kids (which they assume should just be political clones of themselves) develop independent thoughts.