Look at this question: Does the universe have a center?. (original, unpopular)
Now, look at this one: Did the Big Bang happen at a point?. (duplicate, famous)
Looks like a paradox, right?
In summary, we see that the original question is closed, being unpopular, but the duplicate is not. Does this imply we should not mark a duplicate post as a duplicate if the original post is not-so-popular?