K.:.
I think he should go because it's the right thing to do. School employees are taking time out of their personal/free time to help honor the students. I think it's disrespectful not to attend a ceremony in which you will receive a special award. Kind of like a slap in the face, or being a poor sport. I think if he doesn't want to go just to be a brat (which it sounds like he's being), then he doesn't really deserve the award. He's a teenager, he's being ornery because that's what teenagers do. He'll be mad at you for making him go, but he'll forgive you, once he's on the stage & you're clapping for him.
On another note, is there a special treat you could entice him with? Dinner or dessert, after the ceremony?