I think the root of the reason Trassk doesn't want characters to die is because, well, Blizzard this is has killed only 1 character in WoW properly, and that was Bolvar. Alliance players liked him, he wasn't a douche to the Horde and we saw him 'die'.
Compare that to Fandral. We all know he was up to something with Malfurion, but what do we get? His motives explained in a book, and him being made into fodder for the Twilight's Hammer. Why didn't Malfurion make an appearance in the fight? Why were the Druids of the Flame, Night Elves who disagreed with Tyrande/Malfurion, all put under the villain category?