“Hillbilly Elegy,” Ron Howard’s mystifying film adaptation of J.D. Vance’s best-selling 2016 memoir of escape from a hardscrabble childhood in Middletown, Ohio, features an early scene in rural Kentucky, where the character of J.D., in voice-over, tells us he was always happiest, and where his family’s Appalachian roots were. The protagonist, played in childhood by […]