She also completely destroyed every culture that used interdimensional travel. Whole civilizations collapsed as everyone was yeeted back to 'where they belong', and no travel, trade or commerce is possible now.
Do you know what happens when society collapses? People die. A lot of them. Famine, violence, and general disruptions effecting every dimension-hopping culture (and there were a LOT of them over the series) would result in the deaths of billions. To say nothing of earth, having an entirely alien and profoundly hostile biome dropped into ours. How many humans were butchered by bands of monsters and obscene super-beasts just appearing out of nowhere.
But hey, Star got her spic-dicc and post-modernists are all about subjective morality, so I guess the deaths of billions of innocents and the extermination of an entire category of beings is justified.