Armor is (and always will be) a constant balancing act between protection and mobility and comfort.
Of course people want to shed unnecessary heat and weight. Those in positions where they're not actually getting shot at (FOBBITs) have already done that risk v. consequences math. If you're in a unit where guys are constantly taking small arms hits and purples are typically going to wear GI gear.
Note in the .pdf reference above that USSOCOM has a minimum required level of protection, vice a different performance standard.
Those who know they're not even going to hear a small arms shot during their tour (let alone actually see one splash around them) will buy an operator-ish Condorsofterwhispylight rig to style around in between the APO and DFAC. Backface deformation is nowhere in their stream of consciousness.
...and oh, if they see JSOTF troops or Rangers walking around, everyone wants the latest (even better in a non-standard color), just to poke at the First Sergeant or CSM).