Sheamus' runs as a happy-go-lucky babyface are entertaining, but not in a way where he's any more entertaining than say, John Cena. There's a short shelf-life for muscular white guys who hit people really hard in WWE, and if a babyface doing that, you're certainly a number two behind the one-time "Master of Thuganomics." In turning heel, Sheamus is able to showcase more depth and scope to his character, maybe doing some more mat wrestling or having a more sadistic bent to his hard-hitting attack. As well, he'd have great promos to cut because from helping old grandmothers save kittens from trees to doing countless "Be-A-Star" events, he's been such a great "face of the company" for WWE that he'd have ample material for his heel run.