All managers inherit an organizational history. In any human institution, outside of new start-ups, someone came before you. That someone designed processes (consciously or not), molded culture, hired staff, and made decisions. These were not your ideas. You may not have made similar choices given the original circumstances, nonetheless they are now yours.
Being a victim of history is neither bad nor good. It is simply is a fact of life. The trick is whether you want to behave like a victim or not. Managers who accept what they have inherited as inevitable become victims of history. Managers who challenge every aspect of the past create the future. They accept nothing as status quo and make a difference by denying the tyranny of organizational history.