My theory: The DEW conspiracy theory is being thrown around as a way to discredit the idea that the fires could have been intentionally started to burn the areas of the island desired by developers. Sort of like the "baby-killing, blood sucking elites control the world" is a way to discredit the idea that there are elites controlling the world. This seems to be a common tactic to discredit valid "conspiracy theories"; throw in an outrageous version of events to make people ignore completely rational theories of events.