Because the law is recognizing something that didn't happen. If I transfer my copyright to someone else, the law then views that person as the originator, owner

Because the law is recognizing something that didn't happen. If I transfer my copyright to someone else, the law then views that person as the originator, owner and creator of that work, legally speaking. But it is not true. I created the work, not the person to whom I transferred the copyright, and no legal formality can change that fact. The law is saying something that isn't true. I suppose all ownership is this way. My answer, then, is that creating something is fundamentally different than owning it. Your creation of something isn't property that can be transferred.