The reason I like nice flat audio response is so that you are not fighting the natural tendencies of the mic to color your sound with artifacts from it's design. This means you are in control of what sound you get via processing. Since stock CB's have rather restricted audio to begin with the last thing you need is to fight a mic's. Since people running hifi, direct inject, asymmetrical modulation are running rack gear or PC audio software anyways it is just better all around to have a flat response and adjust as needed.