I proposed to the boss of the publishing company to add a record with that method, for the student to be able to hear how to play. He told me:"No! Nobody does that, and we vill never do it!".
Several times, after that, I've heard the same answer to some ideas I had. Specially from a partner, in my recording studio CBE, in Paris, when I decided to order a 24 tracks recording machine ( the first one in Europe!), to a swiss engineer, Gunther Loof, who was from Studer. He said that it was stupid, that nobody will use it more than one day a week. But, as I was the boss, I ordered this machine, and we became the most famous recording studio in France, 2 years after we began.