Whitetails around here are small, and a whole slew of them are killed every year with .222s, .223s, and .22/250s. They will work all right when everything "goes right". How often in your life does everything "go right"?

Many hunters have a very vague idea of terminal ballistics, at best. If a cartridge/bullet combination works once, "well, it's a surefire deer killer!" Guy on my lease two years ago had his son shoot a cull buck with a .22 Hornet loaded with Sierra's 40 grain Blitz. Kid took a neck shot, and had a dead deer. Had no idea what a poor bullet choice he made, because "my buddy loads these special, see?" Off just a bit, and there would have been a nasty surface wound, and a cripple.
Another hunter killed a 100 pound doe with his .300 Winchester. Dumped her on the ground , a DRT kill. When skinning her out, he talked a mile a minute about how his powerful .300 was so much better than those standard calibers. Bullet was completely disintegrated! Shed it's jacket, core gone to pieces, classic bullet failure! He didn't understand. Hell, it killed his deer, didn't it? I started to point out that if he had shot an animal where he really NEEDED the power of a .300 Winchester, he probably wouldn't have penetrated the chest cavity, and would have a had a cripple, or a slow, painful kill. Any bullet that went to pieces on a hundred pound doe was not going to work very well on something tougher. I gave up.