I think they did a nice job with Kofi, at least in terms of his promos. He wasn't an ultra powerful, Hogan-like face, but his drive and motivation was there and the story was really good!
Sadly, his last match for WWE Title was really short, but there were good things for him.
Despite everything, New Day is a strongly booked babyface team. They strong-armed that act until it worked, after all.