Evidently, you haven't been personally close to anyone with Alzheimer's disease.
Actually I’ve been close to both. Those with Alsheimer’s were sick through no fault of their own. The pot smoker’s were voluntarily stupid and in denial. Pot smokers, like all addicts will defend their habit against all reason.
The current “science” whose findings inspired this article is nothing more convenient results for a new money making venture. If only weed supporters and smokers could be the only victims of impaired surgeons, bus drivers, etc., etc.