Insights like that were big in the exploitation movies of the 1970s. The dialogue clanked along from one dumb profundity to another, and the sentiments were as pious as political speeches. One of the characters in “Switchblade Sisters” (1975) quotes approvingly from Mao's Little Red Book, although enlightenment among the Sisters is not universal: After the leader of a boy gang rapes a new member of a girl gang, he asks, “You all right? You were asking for it.” She is inclined to agree. “Switchblade Sisters” is one of the countless films viewed by Quentin Tarantino during his no...