Plenty of countries have this. Examples of forbidden names are “Hitler”, “Asshole”, “<Insert demeaning word here>”, and “Quisling” (name of a Nazi collaborator, commonly used as a synonym for “traitor” in daily speech).

The point is that “stupid” is defined as a name that is objectively likely to severely negatively impact the child. It’s not based on “I think X sounds stupid” but on whether “X” carries significant cultural baggage like being the name of a famous Nazi, a slur of some kind, etc.