Kyle,
I have a theory that any activity that takes us out into the public arena for a period longer than say, an hour or so, requires some type of uniform. Consider church, work, school, spectator sports, etc.
Consider also the fact that golf came from traditions where actual club "uniforms" were worn until the latter past of the 19th century, and it's actually a bit surprising that we are able to play our game without some type of consistent conformity with established norms.
I'm not projecting any value judgements on this phenomenom, mind you. I'm simply trying to explain how we arrived here.
I guess the good news is that golf fashion. to some degree, at least seemingly tries to model itself on whatever might be seen as fanciful dress for the particular time period, whether that be plaid Sansabelt slacks with a 3 inch thick yellow belt, or the tight-fitting, ultra-short-sleeved, collarless black pasted on shirt of the present European tour.
I also think on some level, we try to show respect for each other through what we choose to wear. If I showed up at some traditional private club wearing short shorts, a muscle t-shirt, and a sideways cap I would dare say that while I might be flexing my individuality, I would also not be respecting the wishes of either my hosts or the other members of the club, so simple Miss Manner courtesy would suggest that it's best to err on the side of what's generally seen as acceptable.
This is all, of course, from a 1970s rebel. However, just as important as it is to keep an independent mind is to choose what things are worth fighting against.