At the range there are two crowds who shoot 40 S&W for two difference reasons.
1. Experienced shooters who want to try a 40 S&W.
2. New concealed carry permit holders who shoot them because some jackass salesman at a gun store convinced them it was the caliber they needed.
And, as if .40 S&W isn't uncomfortable enough to shoot with standard pressure loads, the same jackass who sold the uninformed/inexperienced newbie his new gun, also sells them the most expensive / "hottest" self defense ammo to practice with. "Gotta break in that new gun," he says as he smilingly rings up the sale.
WRONG - you forgot about the many who love .40S&W, which is my first choice as a defense caliber. .45auto is second. 9mm in third place. I love .40S&W and chose it as my carry-gun caliber because it combines ballistic capability near that of .45auto with capacity near that of 9mm - and is wonderfully soft shooting and enjoyable to shoot.
You obviously don't know much about .40S&W, nor have much (if any) direct experience with different pistols chambered in .40S&W.
Owning and comparing my G23 Gen 3, G23 Gen 4, G22 Gen 4, two Browning HiPower 40s, STI Edge 40, M&P40, two M&P40 Compacts, HK VP40, SIG 229, SIG P320 40's in Full, Carry, & Compact sizes - I have a relatively thorough experience with the caliber.
It's an awesome caliber that is exceptionally comfortable and enjoyable to shoot depending on your choice of platform (anything BUT Glocks) and bullet weight (180 gr is awesome - feels like a very soft shooting version of 230 gr .45 - NOT "snappy").
Anyone who thinks that firing 165 gr defense loads in a Glock 23 (admittedly a comparatively unpleasant combination, as compared to other options) equates to "knowing" the .40S&W caliber has got a good bit of growing to do.
I think most people who say .40 is uncomfortably "snappy" to shoot say so either through hearsay or from having fired 165 gr defense loads in a Glock 23.
Fire some 180 gr defense loads in an M&P40, SIG P320, SIG 229, Browning HiPower 40, HK VP40, or an STI Edge and your opinion of .40S&W caliber will forever be changed. It's a pure pleasure to shoot, given a proper platform for the caliber. Great momentum/barrier busting without deflection, high capacity, and a joy to shoot - all the reasons why .40S&W is such a great caliber. Anyone who hasn't experienced this personally doesn't understand the wisdom of choosing .40S&W.
For those who require lower recoil, less costly ammo, or a small pocket-size pistol, 9mm is a perfectly acceptable alternative, but it is not necessarily a "better" choice as a caliber. It is just a different choice with different suitabilities.
.40S&W remains a great choice as a defensive caliber and will continue to be one of the three most popular pistol calibers you can choose from for many years to come.