I want more people to enjoy music, which means being honest with what comes with each method. Piano apps will be easy and cheap, but they have their limitations. Marketing and comments like the parent make it seem like you can just substitute a teacher and practice by using these apps. I also imagine that people can get frustrated if they see that after tons of practice they still don't sound how they like and they don't have a lot of tools to improve by themselves, because you don't get those tools from apps.

And you're not really understanding me. I don't feel like these apps cheapen my effort. I just wish I knew the things I talk about in my comment earlier so that I could have taken the piano classes I had more seriously and I wouldn't have to suffer now the lack of technique, exercise and repertoire I have now.