We have to remember that this outbreak is happening against a background of "normal" numbers of acute respiratory failure (ARF), acute lung injury (ALI), and acute respiratory distress syndrome (ARDS) --- which can be happening at rates as high as: 77.6–88.6, 17.9–34.0, and 12.6–28.0 cases/100 000 population per year, respectively.
Contributions to the epidemiology of acute respiratory failure
I'm sure the CDC is more than well aware of this, but aren't pointing that out anywhere. This would imply that at least some of the existing cases are "background cases" that, because they happened to people who vaped, get classified as "vaping related lung illness".
That, at best, must be a serious confounding factor, and at worst (for tinfoil hat wearers), could mean the whole outbreak is an invention constructed entirely from background cases that happened to vape.