^Saying that creativity "should" only be approached in a certain way is advocating censorship, or at least it's the first step in that direction and should be guarded against carefully.
Your problem is that you're defining originality in a very narrow and illegitimate way, as being solely about making up new character names or settings or whatever. That's complete rubbish. Like I said, originality is in what you do with the ideas, not where they come from. There are countless examples of creators taking pre-existing characters and plots and doing wildly original things with them, and there are sadly even more examples of creators inventing new characters and situations and doing painfully unoriginal and cliched things with them.
This doesn't mean you can rip off a premise or a plot situation. Reexpressing the concept is one thing as ideas can't be stolen except for their ultimate expression.