“As far as I can tell, film is one of the few artistic mediums to rejoice in utter failure. No one revives hack 18th century opera or hangs paintings by Rembrandt’s butcher. But just try to rent a copy of “Battlefield Earth. The cult of bad movies doesn’t revolve around big-budget disasters so much as the penny dreadfuls of mid-century American cinema, the discreditable, low-budget horror movies peopled with attacking 50-foot women, killer shrews and aliens with zippers down their back. You’ve got to love any film in which Martians wear Timex watches. What makes these films so watchable?”