I recently posted this question: Has this function been described/discussed?
It received two downvotes, and no explanation on why it isn't a good question. It received one answer, which got one upvote (by me, because even if it didn't actually answer what I was asking, it pointed me to aspects that I didn't realise could be at play) and one downvote. It also got several comments, most of which helpful (one of them actually came close to being an answer, pointing to the similarity between the function in question and Dirichlet's function - so it seems to be not completely unreasonable).
So I am asking, what makes the question deserving of downvotes, so that I don't commit the same mistakes in the future?
Or is this just a case of newbiephobia in the internet?