Basically, it's the idea that the traffic stop has NOTHING to do with me being armed. To begin with, I don't get stopped often since I make a concerted effort to obey traffic laws. That doesn't prevent me from being stopped for an inadvertant error like a light not working or just a bored cop looking for some action.
I personally don't care to be treated as a potential murderer just because I have a bad bulb. The premise that anyone with a gun is a danger to a LEO or any other person needs to be changed. I went through a discussion of this on another forum and it went all sorts of sidewise.
A person who carries a firearm legally is no more a danger than a mechanic who carries a wrench in his pocket. If the cop wants to ask if I'm armed, I have no problem answering and producing my license(actually in MO, it's an "endorsement" ON THE DRIVERS LICENSE).
Over 8-9 years I've had a CCW permit, I've had maybe 3 encounters with a LEO and was asked for my drivers license(once each in MO, KS, and Iowa). Each time the officer knew I had a permit from the response on the DL(since it is an "endorsement" on said license). The MO and KS troopers didn't even mention the fact but the city cop in Iowa got all sorts of hinky and wanted additional information like registration, insurance, and even asked to look through my Jeep (which I refused). That was prior to Ia passing the CCW law and I'm sure he was fishing for a sucker packing across the line.