I do SS myself, but one of this article's requirements is he can't be bothered to go to a gym or to buy large gym equipment for his home. And he wants to do the whole workout in bits and pieces no longer than 30 minutes. With those kind of restrictions, dumbbells do fit his lifestyle better than barbells and I'm fine with that. There are many quite effective exercises you can do with dumbbells. Yes, dumbbells are sub-optimal compared to barbells, but he seems okay with sub-optimal, since his primary qualification seems to favor convenience over effectiveness.