No, it’s not “ethically ambivalent.” It’s ethically 100% okay. Moreover, copying somebody else’s original idea is 100% legally permissible, so long as you’re not copying their expression of that idea. 17 U.S.C. s. 102(b) (“In no case does copyright protection for an original work of authorship extend to any idea…”).
This is fortunate, because you, for example, are not the first person to have the idea that copying ideas is bad. Somebody else had that original idea long ago. But because you (probably) did not copy their expression of that idea, you are (probably) not liable for copyright infringement.
