Why is this not legendary? I mean it has huuuuuuge backstory to it. It's been in Warcraft lore since forever. Illidan's swords are legendary and they barely have a story behind them.
Well, I've noticed that with just 2 exceptions (and they're slightly weird ones too) all legendary items in Wow are weapons. Part of this is probably the visualaity of them: I see a guy walking down the street with one of the war glaives, and I know not to mess with him. But I wont notice a trinket that isn't even visible.
Anyway, that's my take on it.