Our uniforms are like... A polo and BDU's. No place for a badge. Even if wearing a typical "uniform" type shirt, no badge. My thought on wearing a badge are this:
Dude A: Has a gun, wants to kill himself, someone else, is drunk, high, et al.
Dude B: Is wearing a badge (and has a gun to defend himself)
Dude C: Came to take the loser of the battle to the ER.
If Dude A recognizes Dude B as a cop, b/c he has a uniform with a badge. He may also recognize Dude C as a cop, b/c he has a uniform with a badge.
I like to separate US from Police. People tend to be more open if we're not PD, and may possibly be less likely to kill us, if they recognize us as "Not the cops". Then again, they may just want to kill us, too.
I don't know if that makes sense, I've been drinking.