It's our European heritage. Most of the European nations have significant regimental alterations in their dress (some even combat) uniforms. And its spread far and wide.
Each a unique uniform within a different army and yet uniform within each unit. Why should Canadians all look "blandly uniform."
I'm all for regimental distinction but am against skittle parades where within a subunit you have individuals with major uniform differences which make them stick out like a sore thumb. It goes against my Teutonic sense of order.