I think you guys are being a bit too hard on the people who carry without one in the tube.
I mean realistically, how long does it take you to rack the slide? I guarantee it takes less time than it does to lift your shirt to grab the butt of the weapon. Less time than it would take to drop your groceries.
Racking the slide takes a millisecond. It's done with the free hand as the weapon is drawn, like cocking the hammer on a wheel gun. As the weapon moves forward the free hand swipes and puts the gun to ready.
I carry with one in the tube, but I'm not going to think for a minute that I can draw faster than someone else that still needs to rack their slide.
The ONLY downsides I can see is if somehow the weapon jams, or if you first get shot in your non-dominant hand and cannot easily rack the slide for your reply shot. Other than that I believe carrying a weapon without a loaded chamber is safer (obviously there have been accidents when the gun is live) and if it makes a person feel safer, I say live and let live.
I don't mean to get up on my soapbox, but let's not be cruel and imply if someone doesn't carry at the ready they are either less of a person or not as smart as they could be.