A no-answer answer might just be a way of increasing the numbers on one's personal information page. It feeds the "I'm better because I have the most" egos even if there is no monetary value.
I've sometimes wish for a meme that shows "I read this" in addition to "like" simply to acknowledge that it was not ignored. It could mean either a lack of interest or knowledge in subject, or no opinion or simply no answer. It simply says "I read it" It would show new members that they are not being ignored if they begin a thread that has very few responses.