Streamline, streamline, streamline. Extra/different uniforms in the seabag equals less room for my PS2.
In the midst of a seabag pack now, and since I can't get a straight answer from my sponsers, I am subject to packing 2 different sets of mess dress, SDBs, whites, chokers, khakis, and of course 3 different pairs of shoes to go with them (the dress sh!t is for all the grip and grins I'll be doing my first month at my next command). All in addition to flight gear. I love aviation greens and dress khakis as much as the next guy, but the less crap I have to shove into a bag, the better.
Khakis going away (if it happens), will be a sad day, but we'll all get over it. Hopefully the change will last and guys won't have to buy all new uniforms in 5 years.