I just wanna point out non-demon hunter NPCs have been using glaives (of both the 'multi-bladed throwing weapon' and 'two-bladed sword' varieties) since launch day of Vanilla. There's even a night elf shown using one on the original World of Warcraft box art. This fiction that only demon hunters are smart enough to figure out how not to cut themselves with a warglaive is a bunch of horseshit that was just part and parcel of the standard showering of attention hero classes get in order to encourage players to try 'em out. Which is fair play, but demon hunters are old news now, it's going on two expansions since they launched.
Time to open up warglaives for non-demon hunters; if lore's such a huge sticking point all of a sudden for people who never gave a shit about lore before weapons came into question, have the night elves, trolls, and blood elves teach everyone else their secrets of spatial awareness.