And in the present conflict, we wound our enemies, the rest run away, and we are left to take care of their wounded, tying up our resources, increasing our logistical tail, and giving the enemy propaganda to use against us. Interesting how that has worked out for us.
Although this statement can be found everywhere, I believe that it is largely an urban myth. The primary logic behind moving to jacketed bullets at the end of the 19th century was to reduce the extrodinarily bad wounding that was associated with late century bullets - 45 caliber 200+ grain soft lead slugs created ferocious damage, resulting in a huge number of amputations due to smashed bone, etc. Also, the use of jacketing resulted in far less barrel fouling.
Only after the fact did soldiers discover that the jacketing reduced lethality (which they often overcame in the field prior to the 20th century by shaving jacketing off the end of the bullet, creating a field expediant jacketed softpoint)