Why does Spirit Daily continue to spread the devotion to this "apparition"? It is miraculous that this priest, with God's grace and the intercession of the saints, was able to turn his life around. But I don't think it "authenticates" Medjugorje.
You’re correct that Medjugorje has not been authenticated, which is true for about 99% of Marian apparitions. However, the Church has also not gone to the other extreme, as has been necessary in some cases, of declaring it false or fraudulent. So it’s in that limbo (pardon the pun) where it’s permissible as a “private devotion” yet without any official status. Therefore I think you’re right to reserve a bit of caution, as I do as well, but on the other hand, I hesitate to throw any cold water on others’ enthusiam, because isn’t what happened to this one man a miracle in itself?