When I go elk hunting, I want (need) all 3000 FPS from my 300 Win Mag.
When I use my 460 S&W revolver for deer, I want (need) all 2000 FPS.
But neither of these would be the choice a mass murderer would use.
It really doesn't take much to kill a human, if you limited MV to something considered less lethal on humans, you would necessarily eliminate all effective hunting rounds for medium to large game.
But, I am okay with reasonable magazine size restrictions.