I'm not a fan of patents, but in that case, it's not like some bigco seeking to perpetually extend monopolistic rights on some product - the inventor is alive, they made what seems like a genuine contribution to the world, and that contribution is very concrete and complete - not some hollow vaguely generic not directly usable "design".

So it's actually a case where patents are a good fit: the inventor gets to decide the life of their design (and make a bit of money out of it) before anyone can use it freely.