"The machine gun was considered so horrible that it prevented wars from occuring."
The crossbow was considered so unethical and immoral that it was outlawed by the Pope in the 1100s (or around that Medieval time period).
It was outlawed because it allowed a common peasant to shoot a projectile that would penetrate knight armor
Somewhat like the hysterics we get today over ammo that would penetrate body armor or threaten armored limos