It's meant to be a question and answers site, if they want it to be a reproduction of the manual they should just link to the actual manuals. I feel it completely defeats the purpose of having a community to help others if it's not meant to be forum-esque.
To do this, they've already got the tech to identify similar questions. They should just leave all the variations of the question open, and have a prominent "Similar Questions" list displayed for all of them. That would encourage question titles that express what makes them distinct from similar questions, and give people the option of finding the most appropriate variant and getting an answer for that specific variant.
If it truly is not a duplicate question, then it should not be closed as a duplicate. However, many people asking new questions either don't search or are unaware that their question actually is that other question.
Leaving a question open doesn't help any of the google users and instead makes it harder to find the canonical answer to the question as little tidbits of information are scattered around.
If the canonical duplicate target is insufficient in answering the question, add an answer to it that does a better job than the other answers.
> It's meant to be a forum to help people, not rewrite the manual on a programming language. If there was only one way people should literally just RTM.
Actually, it's not meant to be a forum. It's meant to be more like a manual, the manual that no one has written (because the SO manual [potentially] covers everything, not just one product or package or library).