Why did Perrault and Francois evoke respect, although not affection, from Buck?

Perrault and Francois earn respect in the form of punishment and the occasional reward. They work with the team, and they make no secret of their expectations of the team. None-the-less, they do not show affection, the dogs belong to them, and they are replaceable. There is no room for affection or love between man and beast.