Final answer:
Thornton was camping alone due to being outcast and living in isolation after conflicts with enemies had altered his perspective on solitude. His experiences of loneliness and hardship likely made him an empathetic and kind-hearted master.
Step-by-step explanation:
Thornton was camping alone because he had been living a solitary life, akin to a black fox, after being driven from his community. This feeling of outcast had left him yearning for the companionship that comes with human interactions such as the sound of a voice or the touch of a hand.
The isolation was a stark contrast to his previous experience as a rider guarding the herd, where the night's loneliness did not bother him. His solitude was intensified by the oppressive actions of his enemies which had changed his mind and led him to seek solace in the Utah uplands.
Thornton was the ideal master because of the empathy he gained through his own experiences of hardship and loneliness. This made him understand the value of companionship and kindness, likely leading him to be more compassionate and considerate as a master.