Why can duplicates be marked as duplicates?

Question

Should I use whose or which's? has been closed as a duplicate of several other closed duplicates (Usage of “whose” not referring to a person, Possessive "that's", Possessive connecting word for inanimate object). I cannot cite other specific examples of this happening, but I remember it as more than rare, albeit less than common. In any case, this is unhelpful to future users who stumble across such questions—they should be directly linked to a non-closed question.

Possible ideas for fixing:

• Do not allow duplicate questions to be marked as the anti-duplicate. (By anti-duplicate, I mean the question that the duplicate is a duplicate of, if that makes sense. I don't know what to call it.) If Question B is marked as a duplicate of Question A, SE should not allow B to be linked as a duplicate of Question C.
• If a duplicate question is proposed as the anti-duplicate, put that question's anti-duplicate as the anti-duplicate. If Question B is marked as a duplicate of Question A, and then Question C is marked as a duplicate of B, SE should automagically link to A instead of B.

_{My apologies if I haven't asked a good question or if I haven't tagged this right. If I haven't, please feel free to correct me.}

Answer 1

It's not obvious to me there's anything wrong with the current system.

Note that I don't mind questions being closed even if they're not exact duplicates - if the original can easily be enhanced with minor edits and/or a new answer to address both questions, that's what I'd rather see.

Some (but not all) of the "possible duplicates" in OP's link have been closed themselves. I haven't checked them out in detail, but it's possible some of those that haven't been closed could be - either immediately, or following some minor changes to one of the other questions/answers.

We get a lot of questions covering essentially the same ground, but sometimes it takes a really good question/answer combination to highlight exactly why they're "the same thing".

Answer 2

"Should I use whose or which's?" has been closed as a duplicate of several other closed duplicates

Actually, a question is closed as duplicate of a single question. The text originally inserted in the question to report the duplicated question is the following one:

Possible Duplicate:
Other ways of saying whichs

The system automatically insert other links, if the users who voted to close the question, selected more than one question (which means a user selected a questions that was not selected by the other users). This is not what happened in this case, as the other links were manually inserted by RegDwight.

As per allowing to close a question as duplicate of a question that is already closed as duplicate, there is at least a case where this is valid.

• A user asks a question (B) that duplicates an existing question (A).
• The question gets closed.
• The user asks a new question (C), using the same text used for B.

In this case, it makes more sense to close C as duplicate of B, as in this case the questions are exact duplicates of each other.

I don't see also any reason for not allowing to close a question as duplicate of another question that is already closed as duplicate. Users should be free to choose the question that is more close to be a duplicate, even in the case the question is already a duplicate.