The idea that ideas can be stolen and that doing so is wrong is fairly new and somewhat "unnatural". So the ethics of "stealing ideas" are not entirely well-defined. I think the only thing that almost everyone agrees on is that the person who had an idea first (or at least popularized it) should get recognition for it.

Huh? Patent systems go back hundreds of years! Yes nobody owns the idea of the lathe. We need to get past that. But for centuries, societies have recognized that someone who spends time and money developing a particular invention or manufacturing process can have legit rights to it