Not trolling, but I think there is a lot of knee jerk group think going on.
1) Just like there was big magnum mania where everyone thought they needed a 300 WM to shoot a deer at 75 yard, I suspect the opposite has now occured. People are now striving to use as little a cartridge as they can get away with even if it is a bad idea.
2) While it is true that just about every 223 caliber cartridge has been used to kill a deer, an Elk, or a Grizzly, it doesn't mean they are the best choice for medium to large game.
3) Nobody is going to come on this forum and say I shot a [game animal] with an inadequate cartridge and it ran off wounded to die a slow, agonizing death. Every post on the various caliber threads will be a success story.
4) IMO - the right answer is probably somewhere in the 6mm Range for deer and the 277-284 range for large game. I love my 6ARC and 6.5CM, but they are almost certainly sub optimal for Elk+sized game. No matter how well I shoot them, they are giving up mass and/or speed to 277-284s
5) if you give up power (say a 6.5Cm), you have to give up distance vs a more powerful cartridge.
Bottom Line:
1) if someone is so recoil sensitive they cannot fire a 243 accurately, a 223 isn't the solution for their deer hunting escapades. I someone can fire a 243 accurately, using a 223 to prove a point is poor decision making.
2) if someone is so recoil sensitive that they cannot fire a non magnum 270/284 accurately, they need to get closer to the target to guarantee a clean shot.