Maybe legitimate, maybe not. I sent a polite email to the school board members, as follows -
Dear Granite City High Principle, Vice Principle, and Board Members,
Concerning today's decision on whether or not to let William Carruba attend prom wearing traditional Scottish Highland attire, I sincerely hope that permission was granted.
In recent Halloweens, we've all seen the PSA's "We are a culture - not a costume" and the same sensitivity must be applied in this case. For many, a kilt is not just a funny prop, a piece of gag clothing, or a source of cheap laughs - it's a well respected garment, steeped in the history and tradition of our ancestors. To say that men must wear trousers in order to dress like men, is incredibly insulting, and can easily be taken as an accusation of transvestism.
You must ask, would you bar students of Japanese descent from wearing the Kimono? Students of Indian descent from wearing the Sari? Students of African descent from wearing the Dashiki?

I would also ask that any teacher or faculty member that had denied Mr Carruba permission to wear the Kilt be given some cultural sensitivity coaching.

Thank you for reading, and kudos to you if chose against the belittling of another culture's dress.
- Nathan Gill