At the end of 2017, I posted a question here. I was looking for references for something that is very clear and intuitive, but not really mentioned ANYWHERE. I got no answer, but a few comments which were also not satisfying. Time went on. I wrote the first reference and posted it as an answer, because I'm trying to be a good little SE member who doesn't abandon his own questions when he found an answer himself. Then, and only then (because the question was active again) I got some downvotes. I felt a little bit indignified, but ignored it, since it just means two or three particular people don't agree with me on the quality of my question and answer.
Today I saw the question was put on hold as off-topic by 5 users. Now I would like a clarification.
Given the site of on-topic themes I guess people think my question is "too elementary" and not "research level math questions", so not "the sorts of questions you come across when you're writing [...] articles". I would like to clarify that I posted this question on Math Overflow for a reason. I got ten times the reputation on Math.SE than I have here. But I was writing an article. I was doing research. I looked into at least 20 books about graph theory in persue of a reference. There is none. I agree that the problem in the question is an easy one, that can be solved fast with a little bit of thinking. But it is not like I asked "Does $\emptyset\subseteq A$ hold for any set $A$?", because THAT is mentioned in almost every book. My problem isn't anywhere.
So yes, a little bit indignified here. Given my medical circumstances it is good to write about it. But my main problem here, the one why I'm writing this meta question in the first place, is that I want to understand Math Overflow better. From my point of view, I had a question about basic research, which is, to my understanding, a legitimate area of research. Are basic research questions not wanted on Math Overflow? Or is there another reason my question doesn't qualify? Do I need to list every single graph book I can access and explain how the problem is not adressed there?