This is a tricky one. Tutorials are not allowed, and it might set a dangerous precedent that results in people using that question/answer and its (what I imagine will be) high number of upvotes as an excuse to ask similar questions.
We definitely don't want to encourage that sort of behaviour; I've removed the Tutorials tag from the question as I can't see any good coming out of keeping that. It's harder to argue with someone that a Tutorial request is off-topic when there's a whole tag dedicated to the subject, and not just a couple of questions.
On the flip-side, the answer you've given to the
hook_menu() question, especially, is exemplary - there's no question in my mind that it should remain on the site. It will almost certainly become the canonical source of information for the large number of questions we get from people too lazy to read those docs. Of course those people will also be too lazy to read the whole post and will clutter up the site with some other crap instead, but that's a different issue...
So in my opinion, keep the question/answer, but don't refer to it as a tutorial. If possible change the question to cover a real world example, so it cannot be accused of being overly broad.