Having a dog around the house is a joy. You would be able to play with it and also take it out for walks. You would be able to spend a lot of time with it and you would not get bored even for a minute. Even the dog would feel the same way when it is around you. It would become very anxious if it gets separated from you for a long time. But schutzhund trained dogs are not like that.
It might sometimes be necessary to be away from your house for a long duration. It could be because you were given an assignment in your office which would mean that you have to travel a lot and it would be quite a few days before you get back. In such scenarios, your dog would undergo a lot of anxiety and cause a lot of problems.
But there would be no such problem in the case of schutzhund trained dogs. Even if you go away for a few days, they will wait patiently until you come back. They would know that you would not abandon them and they would be disciplined throughout the duration of your absence.