There are many valid contentions here, and they tend to reflect the type of training that the respondent has engaged in. Honestly, I am not looking to start an argument, but how many of us here have engaged in training beyond bad breath distances? How many have truly tried to see how far away they can successfully engage a target?
Before it is tossed back at me, chances are very good that range proficiency will quickly fade in a firefight. But really, how many people here plan to not put up a fight just because the threat is beyond their trained for engagement distance?
Perhaps it is because most of my life I have been a rifleman, I like to stretch the legs of my handguns. Not in any particular order, I have engaged in: NRA 2700 Precision Pistol (out to both 25 and 50 yards), both 25 and 50 yard PPC matches, and 200 meter IHMSA matches. Shooting at silhouettes with a revolver out to 220 yards/200 meters, can be scary, challenging, and satisfying!
Why carry extra ammo? First and foremost, chances are very good that if I am unfortunate enough to find myself in an engagement with an adversary outside of bad breath distances, I may be the only hope of neutralizing the threat, and NO, I don't plan on wasting valuable ammunition using "suppressing fire". If the threat is outside of traditional engagement distances, and I have a clear field of fire, as long as I have the ammo, I can walk the rounds onto the threat.
How many folks here have ever read the works of Elmer Keith? They can be inspiring when you have an interest in seeing how far away you can successfully engage a target with a handgun. Any artillerymen here? Considering the accuracy and capabilities of a 105mm howitzer, I have often heard the comparison that dropping a 105mm HE round at a target 10-15 miles away is not much different from hitting a target a 100 yards away with a 2" revolver, it just takes some practice!
I challenge you to the following skill test. If your comfort/practice distance is 7-10 yards, put up a silhouette at 50 yards and see how well you hit your target. If your comfort/practice distance is 50 yards, put up a lifesize silhouette at 100 yards or greater (if you have the distance available to you) and see how well you engage the target. You may just surprise yourself! Just because you've never done it before doesn't mean that you can't do it!
Remember, most of us haven't gotten to be as old as we are by playing by the rules all the time, and there are no rules or referees in a firefight!