From my part (since it was I who did this), you had answered the question already on the duplicate.  

Since you effectively had recognised that the question was a duplicate and had correctly answered on the correct question, my role was simple - to play the janitor and thus cleanup by removing the answer.

There was no reason to merge here since you had already answered the question.


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Most traffic to Stack Exchange sites is via search engines.  To redirect users to the correct question, Stack Exchange uses the policy of redirection as explained here:

 - http://meta.stackoverflow.com/questions/125220/automatically-redirect-anonymous-user-from-unanswered-duplicate-question-to-corr

Now ordinarily I would normally leave questions and answers alone unless they start to receive high traffic (visits).  In this case, you had answered the question on the duplicate - thus leaving two answers on separate questions would have been nonsensical - you potentially would be benefiting twice with the same answer.  

Hence the janitorial rule here applies - cleanup and move on to find similar stuff to tidy up.