I mean, if you consider forcing adults to actually pay attention and watch the little shitlings they're responsible for a downside (as most parents absolutely would) then I can see how it's scary.

They consider themselves (at a minimum) entitled to disturb the peace with impunity. They consider themselves entitled to bring a screaming child anywhere they go, regardless of how appropriate or not it is to bring a child. You would never again think parents aren't entitled if you'd ever in your life tried to carve out a space away from them. Look at the reactions to any suggestion a wedding not need to have children present, or any other solemn occasion, mombies and daddicts lose what passes for their minds as soon as you put up an "adults only" sign. They want that sign taken down, and if it's something that's actually harmful to their kids and not just some adults wanting peace that they can invade with their shrieking germ spewers, then they want it banned altogether.

Every vice banned to protect children, and every restaurant with table cloths whose owner is afraid to put up a "no children under 12" sign are a testament to the entitlement of parents. It's a force of the universe only slightly weaker than gravity.