Is it possible for a film to be not bad enough? Maybe that’s the wrong way to frame it. Shoddiness comes not just in quantity but in flavour: there’s good-bad, bad-bad, no-budget-bad, cheesy-bad, doomed-from-birth-bad. Producing high-yield schlock involves a precise cocktail of badness. The problem with The Meg, which feels like the frazzled product of heatwaved heads, is in its badness ratio: not enough fun-bad, too much boring-bad. The Meg, in which Jason Statham takes on a giant shark with growling one-liners and a steady harpoon arm, goes for two genre tones, and ends up splitting the difference. One is the…