Dogs don't criticize your friends. Dogs admit when they're jealous. Dogs are very direct about wanting to go out. Dogs don't feel threatened by your intelligence. You can train a dog.
Dogs are easy to buy for.
You are never suspicious of your dog's dreams. The worst social disease you can get from a dog is fleas. Dogs understand what NO means. Dogs understand if some of their friends cannot come inside. Middle-aged dogs don't feel the need to abandon you for a younger owner.