cause they've never served in a FAO that make you have to trust someone with your life. Where little lover's spats could get a unit killed. It just adds another layer of complexity to a combat situation. Do you press charges for calling someone a "f#g" as sexual harassment? So now you add PC speech to ROE in a combat zone.
Not only that, but doctors aren’t really soldiers or marines. They wear the uniform and get the pay according to their grade, but they are a different breed of cat.