I had the almost complete opposite reaction: the user is telling something isn't working, the author interprets that he needs to fix something for the specific

I had the almost complete opposite reaction: the user is telling something isn't working, the author interprets that he needs to fix something for the specific use case of the user. The user might have found a bug or edge case that's useful for the authors own usage. Perhaps even something the user doesn't need to function, but just stumbled upon. Not saying that this is often the case or the author should dive into every question (the author doesn't have any obligations at all) - there are just too many ungrounded assumptions in the interpretation.