"Similarly, there’s nothing intrinsically wrong with a system in which we stop crediting the original source of the idea—one would just need to find a way to make it practicable. There is no moral bedrock in which prohibition of plagiarism is inscribed."

I think that's the main point of the article, and I agree that there is nothing intrinsically wrong with that. The problem is just that this can lead to other problems. One of them is lying; if you say that you made something you didn't, you are lying. Another one is that you can get rewarded for something you didn't make; it could be e.g. money or a job.

So in order to make it practicable we would have to find a way to either avoid all those other problems, or to make the change so small that we don't get those problems but in that case I don't know if there would practically be any difference.