If you want to enter the Royal enclosure at Ascot, you will be expected to wear a morning suit and top hat. You choose not to, you don't get in - they regularly get gentlemen to re-tie their neck-ties because they look sloppy.
This mode of thinking begs the question again. Why are certain types of dress mandated for certain occasions? Do white tie and tails make the enjoyment of the opera any better? does someone not appearing in the same make the rest of the attendees less apt to enjoy the music? Perhaps it is a total phylisophical question when one, more spcifically I, wonder why the outward appearance has become so overly important that judgement can be passed on a person based solely on it, and not on the individual.

I knew a man for many years of my life before he passed away who was by and large one of the wealthier men in my hometown. He often had great dinner parties and the like and always told guest to "come as you are". He made his fortune farming and grew up a working man rarely to be seen out of coveralls. Because of this outward appearance he was so often overlooked by the higher up crowds, or snubbed by the same. His common phrase was simple " appearance does not make the man". Now he was never a kilt enthusiast, but what I learned from him and his outlook was that if I treated people differently based on judgements made just by the eye then I am doing a disservice to them and to myself.

It seems to me sometimes that people get so wrapped up in the rightness or wrongness of kilt wear that the things that should be more important go by the wayside. Again this could be more of a personal phylisophical search at this point then an academic one.

PS. As an aside, I am thoughroughly enjoying the comments thusfar, certainly providing an ample supply of food for the buffet of thought.....hmmmm perhaps I'm getting hungry and thus the food refferences.