If so many characters on Azeroth are obsessed with finding out more about the Titans, why don't they just ask Alexstrasza, Ysera or any of the other dragons who would have met them personally.
She seems to be quite chatty with mortals these days.
Because Brann is too short, Alextrazsa just ignores him when he asks her anything.
Besides, the more IMPORTANT characters (military leaders) are after the Titan RELICS, you know the big shiny things that theoretically give a 10% zone-wide damage buff? (Wintergrasp)
Unless we could kill the Titans and loot those things and run around with them, I don't see why anyone should bother