Some say they are not dancers, that they don't enjoy dancing, that they are not trained dancers. Imaging people using this excuse about singing songs in in worship. "I don't like to sing. I am not a trained singer. I'm not a singer." That is silly. Everyone can and should sing while praising God.
Just like their are steps of engagement involved from going from simply standing, to singing, and to raising hands, there is another step in involving motion. (Spontaneous or planned movement? That is another discussion.)