“I was surprised to find that a lot of people don’t have a link anywhere to their feed.”
Knight went hunting for RSS feeds by hand and found blogs that have one but never link it. Many also skip the one-line auto-discovery tag that readers like NetNewsWire use to find a feed from a URL. The fix is a single link element in the page head. A feed nobody can find has no subscribers, and every reader who gives up goes back to the algorithm.