Both of you missed the point. It doesn't matter if it's not from my tribe, it still my kin and as such, it's plainly stupid to talk in front of a Troll how you've fought and slain it's very own RACE.
I mean, Vol'jin still showed up to meet the other Tribes back in the ZG to discuss the future of the Trolls and the Tribes. Tribes (even at war) used to meet every year at Zandalar. Not to mention that now we have the Revantusk tribe as members of the Horde, and they were almost extinct during the Troll Wars. The very reason they fled to the Hinderlands was to escape with what little they had.
Forgot to mention, our playable Troll emotes, such as /cheer or /charge, even praises Zul'jin. He is reverenced by almost every single Troll as one of the most important Trolls to ever lived.