Hollywood is often criticized for its constant recycling, but the top six movies at the summer box office are all either sequels, reboots or new twists on old properties: X-Men: Both became hits by irreverently parodying their own crassness as a toy movie and as an unnecessary sequel. [...] the other family films, "How to Train Your Dragon 2" ($142 million) and "Rio 2" ($142 million), have failed to generate the kind of summer box office usually expected of such big-budget animated releases.