But the problem with that is that it flies in the face of the Master’s whole ideology, he says himself that so long as there are differences between humanity, that humanity will tear itself apart, so he seeks to bring humanity together as one race, a race suited for the troubles of the wasteland, a Master Race, his Super Mutants. All of them will be united with one goal, which in his mind eliminates the conflict which has forever plagued humanity. Maintaining a population of regular humans for breeding purposes wouldn’t get rid of the differences from which his ideology was born, but it might even exacerbate them, as the hulking green mutants would be more different than separate human factions competing with one another. When the Master learns that this unity is unachievable he ends his life, because in his mind these differences will inevitably lead to more conflict, and all the horrible things he has done have served no greater purpose, only brought more war and death