No one should care what the naysayers say about any caliber anyone carries. They all work fine.
So many childish people who just love to argue about caliber in the firearms community. It really is kind of pathetic and borderline nerdy.
There are a lot of people who took that room temperature challenge, or visited the ER at one time or another, and I don't think they really give a **** what caliber it was that someone shot them with.
That's not possible when it comes to 40s&w and 7.62x39. To many emotional grown adult men in the gun community for that!
40S&W was introduced as a better compromise replacement for 9mm, 10mm, and 45acp. More power and bigger bullet than 9mm, while still being in a 9mm sized platform with comparable capacity. A smaller and lighter platform than 10mm with less expensive ammo, less recoil, and less wear and tear on the components. Small platform than 45acp with better barrier penetration and capacity.... As a side effect of all this, many, not all, of those who were 9mm, 45acp, and 10mm fanboys all felt threatened and insecure being told their favorite caliber was in someway inferior, so they banned together to bash and hate a perfectly great caliber in it's on right!
Then when it comes to 7.62x39, the AR15 mafia and veterans and services men whose enemies were armed with this inanimate object chambered in x39 all banned together to bash and HATE AK47s and any and everything chambered in what's arguably one of the most battle tested and commonly used rifle caliber on the battle field.
Every caliber has their own pros and cons. They have things they do better than other calibers and roles/task they will be best suited for than other calibers. I can't understand the logic behind hating or disliking any reliable caliber. I like and own 22lr, 380acp, 9mm, 40s&w, 45acp, 38spc, 357mag, 44mag, etc. all for different purposes and roles.