I recently opened up a piano studio after I had several parents request that I teach their children piano. Most of them thought that I'd connect to the kids since I'm only 16. However, 10 of the 13 children I'm teaching, all of whom are below the age of 8, have already told me that they hate piano. Four of them said that they hate me. So I was wondering what you would do if you were in this situation, because I don't quite know how to tell the parents that I'm not going to force their 6-year-old to learn piano.
It may truly be that these kids don't want to play piano at all. BUT, I have experienced with my own kids and their friends that if you make something fun and not a chore (but a "free-time" activity), those kids suddenly think that "thing" is cool.
Kids don't like to be told what to do by their parents, especially in front of others. When this happens, that "other person" (you, perhaps, in this case), may be seen as some sort of enforcer of their parents' vision.
Try to maybe be a bit more conspiratorial with these kids. Teach them a modern song that THEY are into. Make this stuff something that those kids have SEPARATE from their parents.