I think a clothing forum makes as much sense as many of the others. More than one way to organize something. But the general problem is most people just look in this general discussion forum and it's easy for specific things to get overlooked when posted anywhere else.
I for one would find a specific clothing forum more useful than trying to address clothing in specific forums like road, or MTB. I think there is more in common than not when it comes to clothing.
In the end, there is no perfect way to organize this. I think there may already be too many forums, so another is probably not a good idea.