I have no doubt that a 223 will kill any white tail.  But for reasons of chance if I mess up and place the bullet  wrong I may not be able to recover the animal.  Again  that's where I hunt. It's thick.  If hunting a wide open field area where I could see for ever into the distance I'd feel more confident with a 22 center fire.  
I'd prefer a 6mm or a 25 as a minimum for myself.  If someone wants to use a a 223 I see no reason to judge them.  I've seen what 50gr gmx bullets do to bone. No doubt it will work