I allow myself the comforting delusion that I would be skilled enough to use a firearm for self defense, or for repelling the blue helmeted commiezombies that are sure to come some day here
... but I don't think I'd have the cool necessary to put a rifle bullet into a man tied to a firing post at 10 paces.
A little too close to his eyes, if you know what I mean. Yeah, he's a scumbag murderer/rapist/whatever. I worry that my nerves would hold up at bang-time and I would wobble the shot, end up gut-shooting him or something awful like that.
Hanging with a drop-floor actuated by a lever, electronic lethal injection / gas / electric chair are deaths not dependent upon the skill of the executioner.
I think "way back when" that the executioner wore the big black mask for his own sake, not to protect him from retribution via anonymity. It's gotta be downright nerve-wracking to deliberately kill someone who's restrained and awaiting your own personally delivered doom. People who enjoy that type of stuff tend to get captured and put on death row.
Killing in battle, sniping enemy soldiers, clandestine assassinations via knife or poison... they're still different, at least in my mind.