This question is really just to suggest an equal and fair treatment to all the stack members on all subsites. When an OP asks a duplicate question, there is no saying if the question will be upvoted because people didn't realise that it is a duplicate or downvoted for asking the same question again.
Here are some examples where even after asking a duplicate, the question got upvoted:
Then there are questions that get downvoted (and the original questions were upvoted):
I understand that it really depends on the users upvoting or downvoting and nobody can be forced into how to vote. But then the question becomes if it is fair for this inconsistent voting to exist. At times, it almost seems like a good idea to ask duplicate questions because you can still bag some votes. It has been said so many times on stack exchange that duplicates are becoming a hassle, so upvoting the duplicates almost seems like rewarding the OP for asking the same question again. Why not treat the duplicate questions equally and once that a question is marked as a duplicate, remove all the upvotes from the question and penalise with only 1 or 2 downvotes.
I did look at these questions, but they don't really address the inconsistent voting or only answer the question partially: