The funny part of it is I bet the Cadets would have probably changed uniforms decades ago if they could have afforded it, instead of McGyvering (safety pins, staples, superglue, etc.) the old WOOL uniforms they had for ages.
The fact they couldn't afford to replace them for so long probably greater solidified a lack of change as "tradition", rather than a practical necessity.
I suppose these same folk wish George was still rocking that handsome mustache he had going in the 80's... for the sake of tradition?
Anyway, it is a uniform... which, in general, seem a bit awkward in the context of current drum corps. The speed, type and planes of movement that performers are currently executing feels a bit stifled and .... well... square given the limitations of the uniform and shako.
Add to that you are forcing some static, external concept into a creative program (imagine going to a broadway production and 2/3 of the cast are all wearing matching three piece suits and mexican sombreros - regardless of the production - while 1/3 are wearing costumes actually relevant to the program). It is just kind of weird.
Winterguard realized this ages decades ago and made the change. Just like drum corps finally caught up to marching bands of the 80's by adding electronics, we can only hope that drum corps will catch up to early 80's winterguard sometime soon.