We humans love dogs, and we interpret the positive behavior they show us as affection and love, so we invite them to live and work with and for us. Contrary to what our culture wants us to believe, dogs are not human:
Dogs do not have human emotions. They have dog emotions which humans call excited, happy, sad, afraid, confident, playful, angry, etc.
Dogs are self-centered. They do not have a conscience. They behave the way they do—like kill and eat things, dig holes, ignore you when you give them a command, chew your shoes, etc.—because they are dogs.
Dogs do not live in the past or in the future. They live now.
Dogs do not communicate with words. They communicate with body language. They quickly learn how to read human body language.
Because we love them, and we invite them to live and work with and for us, we are responsible for treating them well and for training them to be good canine citizens.