There are hundreds, if not thousands of USAF troops on the ground in Iraq that work nowhere near the flightline. They're out past the wire making sweeps with the Army folks. In addition, the USAF is big on the security force "augmentee" concept where any troop from any career field can be called on to work with the security forces troops for a period of time, following some additional training. So just because someone is a finance troop doesn't guarantee that they'll not be walking the streets, sands, or mountains in Iraq or Afghanistan.
Some guys from Lakenheath got to set up Iraq's air traffic control centers, and they were under fire a few times. I'm not sure what they'd think about wearing blue when everyone else is wearing desert tan but I doubt they would have liked sticking out like that.
I already deploy with 3 uniforms, because the USAF recently banned civilian clothing for off-duty wear while deployed. I don't need/want another garrison uniform. If all they want to do is make a garrison uniform, make my normal blues uniform more comfy, or come up with a non-camo patterned garrison utility that isn't blue.