Being capable is one thing. Overcoming the "not a good enough player to coach/teach me" prejudice in order to get a shot at showing what you know, that's something different. Which is sad, because there are likely a good number of potentially good coaches/teachers who will never get a serious look because they lack the playing credentials. I've seen it happen to people I know, guys who could coach circles around someone who has a (semi-pro)championship ring, but was lost in the shuffle because the head man was dazzled by the bling.
That said, there's nothing like being able to say, "I've been there" to lend weight to whatever point you're trying to get across...