Aerodynamik
personally I would rather see a FULLY trained, experienced and capable person doing the roles.
I think that you'll find that those civilians currently employed in the role together with their pilot and air observer colleagues plus the officers that they support might take umbrage at the implication that they are not fully trained, experienced or capable.
I don't imagine any of them would advocate full civilianisation nor totally ab initio recruitment of observers directly from civvy street, either; but that does not mean that those currently in the role are not capable.