It's great if your puppy did Puppy School when young. But how often does it play and sees other dogs? People with very busy life schedules sometimes work long hours and get home pretty late. So they only have time to take dog out to different places on the weekend.
Please remember - dog socialization is important during all your dog's life.
Puppy School was only the start of it. Socialization should be ongoing.
Dogs are social animals. They thrive on companionship with other doggy mates and learn great skills from each other.
A good dog walker can be a great help for busy people. She/ he can break the boredom of long days home alone. Take your dog for a walk and for play dates or to the local dog park or to the beach. And after dropping your dog home she/he can distribute some fun environment enrichment toys for your dog to get entertained for a long while. When you get home you'll find a happy and tired dog that will love to tell you all the fun things he was up to during the day.