I used to believe that clothing choice should be on the basis of "ecological validity", the whole "well you're not going to wear a gi and go barefoot when you're in the street", blah blah blah.
This was a lie. I was lying. I was kidding myself. Think about it: I do not wear a t-shirt and sweats on the street either. Or wrestling shoes. Or a mouthguard, or a cup. (That said, I generally prefer functional clothing I can move well in.)
Of course we don't wear what we'd wear on the street, to train. Because we'd wreck it. When I'm REALLY attacked while wearing a suit and tie (a tearaway tie, of course), I'll deal with it. I'll wreck my outfit then. As they say of street attacks, ***** happens and you shovel the *****. I'm willing to ruin nice clothes to protect myself or those I care about. I'm not going to deliberately expose it to peril on a daily basis.
Training clothing should be based on comfort and functionality. Ecological validity has really very little to do with it.
The only thing wrong with gis and kooky Asian uniforms is if it is in support of image (self-concept, or corporate self-concept as (a) martial arts badass(es)), AND that image eclipses performance.
Might as well wear regular workout clothes. Most people already own some. But really, strong, loose cotton or hemp, with a drawstring such as most MA uniforms are made of, is almost just as "practical" for self-defense training. (Albeit silly in my opinion, but de gustibus non est disputandum--matters of taste should not be disputed.)
