Every so often I'm really surprised when the world begins to turn in my direction. Several years ago, when I unloaded all my carry/competition guns in .40 S&W, I took a lot of heat. How could I abandon the World's Greatest Cartridge, a veritable laser death ray of lethal efficiency? I said then the were lots of reasons:
1) Ammo development has drastically narrowed the gaps between 9mm, .40 and .45.
2) The sharper recoil made it harder to rapidly make the follow-up shots I believed might be necessary. In small CCW style guns, .40 could be areal bitch -- I refer you to my little Star, one of the first super small .40s.
3) From a reloading standpoint I didn't like the pressure curves on some of the most commonly used powders for the .40.
4) I wondered about the longevity of scaled up 9mms.
There's a lot less love for the .40 out there these days. This is from the When the Balloon Goes Up blog, referencing the Safety Solutions Academy Podcast: