Why do piano teachers hate Ray Manzarek?

I went to my friends house earlier today but when I got there he was finnishing a piano lesson his parents forced him to take. Since he has a keyboard and not a proper piano when she asked what he wanted to learn I heard him mention Touch Me by The Doors and she started yelling at him but then she gladly taught him Dio's Rainbow in the Dark. When the lesson was over he said that all of his teachers wouldn't allow him to learn The Doors no matter what the song. What's with all the hate they seem to give Ray?