Winco, as an aside, I asked the same question, only reversed, of the AMP Team. The answer was that they could not afford to stock the clothing for free issue to officers.
That was patently b
ks as they still had to stock it to sell it too us. The only valid reason was that we would have got new uniforms a lot more often if they were free.
Same reason why so many units wear CS95 all the time.