Emotions vs. Stoicism: Mastering talcoríëf (literally cold-mindedness; metaphorically, cool reason and mastery of passions) is very, very important to the eldrae. There’s a reason why their deep history were days of Glory and War and Wonder and Strife and Terror, and they don’t want to revisit those any time soon.
(Which is not to say they behave like Vulcans; clearly, even to human eyes, they do emote – just have a Stiff Upper Lip, old chap, except among the closest of friends, and would certainly think we desperately need to get in touch with our rational sides.
Also, it should be noted, it is extremely unwise to forget that under the talcoríëf, they still burn. Those who forget this fact, especially if they think they can take advantage of it, tend to swiftly learn that ice destroys even more thoroughly than fire, if not as swiftly.)