On stackoverflow moderators tend to not close duplicates quite so brutually as they do on superuser. For reasons such as:

The asker may pick a new answer.
New answers may be better.
Time affects technology, therefore answers may change.

Why doesn't superuser moderate more like SO in this regard?

For example: I asked this question and the answer I picked was nowhere to be found inside the duplicate for which my question was closed.

This is new and useful information. Now, since the question is closed no one else is able to offer any new insight.