Everyone becomes angered,saddened etc over their comrades death for example, it's just that the Uchiha's awakened their Sharingan more,and became alot stronger during these events. That is what Tobirama was cautious of.
Also you do realize that the whole world was in the cycle of revenge,and hatred right? As Nagato said. You seem to act as if only the Uchiha had hatred,and wanted revenge. The whole world was like that, hence the multiple world wars,and clashes such as the Sand,and Sound teaming up to invade,and destroy Konoha.
But the main villains/antagonist are Uchiha so you act as if they're the only bad guys. Also 3 Uchiha = the entire history of Uchiha since Indra right? lol.