LE is taught AD NAUSEAM they are a target. Cops don't appreciate, enjoy, or otherwise want to be a target; its kind of a shi*** feeling, and puts you on edge at times. It changes your perspective of people in general, and affects how you interact with them, sometimes negatively. I'd venture to say its a bit depressing, too, having to always operate like someone wants to kill you.
And then there are those who, apparently solely because they have the right, volunteer to be a target. Never understood that.
I know and work with a lot of cops, and while they are vigilant, they aren't "on edge" and as nervous as you make them out to be. They are simply cognizant that their uniform--not their weapon--draws attention to them. Sames goes for the military.
As someone who has regularly OC'd for over three years now, I can attest that the vast majority of the general public doesn't even notice; but anyone who carries, openly or otherwise, needs to be aware of that fact every second they are doing so.
Your "volunteer to be a target" is pure hypoerbole and unfounded. Provide some evidence to support your claims, and I'll listen to it; but spout pure opinion without any basis of fact, and I automatically turn a deaf ear...