In support, when there is technical competence disparity between the one who asks and the one who answers it is true.

But I though this was more about developer-to-developer communication where asking a question and expecting immediate answer is also a form of putting your own time ahead of the other's time.

I experience it from the other side on a couple of open source projects. I asked a question, nobody jumped in to solve it, and I had to actually read the code carefully, debug my issue and file a patch. Which kind of makes sense, because I am the most interested and informed person when it comes to my use case. Works the same way for closed communities of colleagues.