John the Savage is an outsider in both worlds because on the Reservation he is the bastard son of Mustapha Mond and is different. In the Brave New World he is an oddity, a freak, an outsider, and a carnival spectacle. John does not accept nor subscribe to any of the values or philosophies the Brave New World touts as important. For these reasons he is an outsider.
he's the bastard's son of the DHC, not of Mustapha Mond.