I think there are just way too many 40’s out there, and it will be widely available for a long, long time. 40 S&W is still the 3rd or 4th best selling handgun caliber. Either way, as new as it is, almost all pistols that are chambered in 40 S&W can very easily be converted to 357 sig and/or 9mm with off the shelf parts in a few minutes. Which begs the question, why is 357 sig not on this list?
Why is the 357 Sig not on the list? Because it is an outstanding fighting cartridge for those who can afford it and control it. It is quite simply a better mousetrap, if one is not a weak female or wimpy soy-fed male shooter.
Bingo. The author is probably a SIG guy, and maybe a 10mm fan also - which is why .40S&W is listed instead (even though sales of .357SIG & 10mm handguns/ammo are a just a tiny fraction of .40S&W sales ;^)...
357 Sig is an orphan cartridge. Not many people want it or ask for it.