The author is being hyperbolic with terms like 'never' and 'you're not good enough'.
That said, a 5 shot .38 was much more viable when most threats you were likely to encounter were similarly armed. That just isn't the case today. In the rare event that we will need to draw and shoot, the attacker(s) will more likely than ever before be armed with pistols holding 18 rounds or long-guns with 30 round mags. Attackers today are also motivated in ways that make them less likely to retreat when engaged by armed resistance. Most mass shooters expect to die at the scene, so they will stay and fight. That's the reality.
A 5 shot .38 makes sense against the 'typical' lone mugger armed with a knife, bludgeon, or Saturday night special who will runaway at the sight of a handgun.
In many cases, the .38 snub puts one at a distinct disadvantage in today's age of terrorists and mass shooters in mall and movie theaters.
American gets it right. He understands threat-evolution.
A J-Frame is marginal against even one attacker armed with anything. But now the threat can easily be (1) multiple armed gangstas; (2) one or more mass shooters who intend to die; (3) one or more terrorists who don't mind dying.
In these situations, you'll almost certainly have to expend lots of ammo for suppression, so you can get to cover, run away, or stop the shooter(s). This is suppression fire, not spray-and-pray.
It will be said: "Learn how to shoot, and you can make your shots count." There's much truth in this; but the people who say it, should consider testing themselves in a simulation where the targets are shooting back. Go play some airsoft or paintball against experienced players. You'll be humbled, you'll learn a lot, and you'll appreciate that a fire-fight with motivated opponents bears little resemblance to range-shooting or even formal "training."
When I got licensed, over 20 years ago, I carried a compact 1911 in .45. It carried 7 rounds. I had a pump shotgun for a car gun.
After 9/11, I thought there could be a possibility of domestic terrorists, so I started carrying a spare magazine. Now I had 13 shots. And I replaced the shotgun with a Mini-14. Two twenties.
Now I carry a 9mm with 18 rounds, and 17 more in the spare.
Police know this. When I was a kid, officers around town carried a .357 revolver. It was what they got in the academy, and most of them stuck with it their whole careers. Some, who wanted more "power," catted-up to the .44 magnum. A few carried the 1911 in .45 ACP. Once in a blue moon you'd see a Browning Hi-Power. Lawmen carried shotguns in their cars.
Now, only a few old court bailiffs carry a sixgun or 1911. Everybody else is required to carry a hi-cap pistol. The shotgun has been pushed aside by the AR-15.
When the threat changes, we have to change with the threat.
If a 5 shot revolver was ever viable, it sure ain't now. Reloading with a speed-loader under fire from two or three gangstas, or from an AK-wielding something, is not possible. Five bangs and a click, and you are now combat ineffective.