This is a fair point. I think part of how Claus markets himself is that he appeals to people who personally relate to a stoic “no pain, no gain” philosophy: people who want to believe that learning guitar is a crucible, and whose feeling of accomplishment is amplified by feeling like they have “the guts to endure hardship to reach their goal.” I compare this approach (and there are others similar to Claus) to CrossFit, which, at the risk of going way off topic, pretty much exploits the blind stoicism of people 25-45 who feel highly motivated to get in shape, but never received legitimate high performance coaching when they were young.
To be clear, I don’t think Claus is trying to deceive people, I think he is simply advocating an approach that worked for him, and he’s blind to other approaches.