Why does Karl Moor become the leader of a band of outlaws in The Robbers?

In Friedrich Schiller's play The Robbers, the protagonist Karl Moor becomes the leader of a band of outlaws primarily due to the machinations of his younger brother, Franz.12

Franz poisons their father’s mind against Karl, leading the elder Count Moor to disown him. Driven by this rejection and a sense of injustice, the fiery-spirited Karl turns to a life of brigandage, defying established authority. The play serves as a protest against a corrupt society that could drive a fundamentally noble character to such extremes, though Karl eventually realizes that violence and anarchy are not acceptable solutions to human injustice.21