I have seen a lot of questions all over Stack Exchange which have a lot of upvotes but are completely against the rules (e.g: Resources for learning Mandarin Chinese and What technical details should a programmer of a web application consider before making the site public?). I actually like these questions and I think it's good that they're not deleted or whatever.
What should be done with these questions? Close as duplicate or off-topic?
Off-topic: I know the Chinese Stack Exchange question might be a weird example since it's a Stack Exchange that's not really popular, but I've seen more on other Stack Exchange websites like this which are closed as off-topic. About the duplicate ones, you can find a lot of them if you just look at linked.