Yeah, because animals can give consent.
No, it's because
you're too irresponsible to have a gun. The more guns there are, the more people will die. Harmless scuffles turn into murder when one party is stupid/drunk/angry and armed.
"If everyone is packing, massacres will be prevented." Or maybe they'll be even more common, as the likelihood that the next loon to snap will be armed is that much greater.
Somehow, other Western countries do just fine without citizenry armed to the teeth.
Dumb scientists! What do they know?
Ever read
The Innocent Man? Sometimes, innocent people are sent to death row.
It appears that some of them have been executed. Do you care if innocent people are executed or not?
Again,
all other Western countries somehow manage without the death penalty. Only in beacons of enlightenment like Texas is it the sole barrier between civilization and anarchy.