They have never met demons in real life either. So what?
No. Crusading is really not a buddhist thing. They do not go out of their way to spread wiolence around the world.
Hello? We are in the world of Cataclysm. Last innocent humans died like five days ago =)
But not “because they are demons and monsters”. They did that because that “various demons and monsters” actively did something strongly disagreeable.
At the end of the day martial arts are individualistic thing. Much like mutations. “Pure humans” are, however, collective creatures. So making martial arts very “pure human” is not only illogical, but theme-unfitting as well.
Exactly until they meet real human army with real armor and real weapons. And, by the way, real battlefield tactics.
Never belive your strong feelings. They are irrational.
P.S. For further reading: count how many non-humans are here: “Thus have I heard. Once upon a time the Lord was staying at Râgagriha, on the Gridhrakuta mountain, with a numerous assemblage of monks, twelve hundred monks, all of them Arhats, stainless, free from depravity, self-controlled, thoroughly emancipated in thought and knowledge <…> together with the eight Nâga kings and many hundred thousand myriads of kotis of Nigas in their train, viz. the Nâga king Nanda, the Nâga king Upananda, Sâgara, Vâsuki, Takshaka, Manasvin, Anavatapta, and Utpalaka; further, the four Kinnara kings with many hundred thousand myriads of kotis of followers, viz. the Kinnara king Druma, the Kinnara king Mahâdharma, the Kinnara king Sudharma, and the Kinnara king Dharmadhara; besides, the four divine beings (called) Gandharvakâyikas with many hundred thousand Gandharvas in their suite, viz. the Gandharva Manogña, the Gandharva Manogñasvara, the Gandharva Madhura, and the Gandharva Madhurasvara; further, the four chiefs of the demons followed by many hundred thousand myriads of kotis of demons, viz. the chief of the demons Bali, Kharaskandha, Vemakitri, and Râhu; along with the four Garuda chiefs followed by many hundred thousand myriads of kotis of Garudas, viz. the Garuda chiefs Mahâtegas, Mahâkâya, Mahâpûrna, and Mahârddhiprâpta, and with Agâtasatru, king of Magadha, the son of Vaidehi.”
“Ripping various demons and monsters a new asshole”? Not going to happen.