I'm not sure I would have called it a 'ladder', and the fine grained tiering into buckets seems overly ambitious, but I'm guessing you'd end up agreeing that there are topics that most beginners will find confusing/unfamiliar. If the end goal is to make it easier to sort talks into tracks for conferences, what's the issue? Do you really think Profunctor Optics should be a beginner level talk, or that using "functors" should be advanced? I'm sure you could argue specifics or make a good case for mistakes made in this chart, but to say "I don't know why John does stuff like this" seems unnecessarily harsh.