The circularity point is worth taking seriously. An empty category doesn't just fail to attract interest, it actively signals that interest isn't welcome, so the evidence you're waiting for may never show up on its own. A single pinned thread is a low-cost way to break that loop: it gives people something concrete to respond to instead of asking them to start from nothing. If the replies stay sparse, that's a real answer too, and it costs little to find out.