Originally Posted by
Leodok
There was someone in the forums who gave his own reasons and I personally really liked them. It was a tauren shaman, I think, not a druid, but I guess it works either way.
Basicaly, he started seeing the night elves less as benevolent, wise and peaceful beings in the northern forests, and noticing certain behaviours they had, like how they sort of try to force their own world view into those who come to learn with them. Telling trolls it's wrong to call wild gods Loa, telling tauren to worship Mu'sha/Elune much more than An'she, that kind of stuff. And he said the contact with troll stories (there's no way they depict night elves as anything other than evil, cowardly bastards) also helped change the way he saw them.
Besides, there's been war for a few years now, with only brief periods of peace (like in WoD and the very end of Wrath). Any tauren could want to kill nelfs because of something that happened in these conflicts. A bit of a cliche, I guess, but it does kind of work.