So an AD* diagnosis is trivial to hack. Moreover, it's impossible to design a diagnostic process that's not easily hackable because, ultimately, everything will boil down to a subjective assessment of patient's behaviour, i.e. a "doctor's call". Furthermore, the more you restrict prescriptions and tighten the diagnostic criteria, the more you increase the risk of denying medication to "legitimate" sufferers. Since the guiding philosophy of the medical community prioritizes "helping people" over "prescription security", the problem of how to keep people from getting "illegitimate" prescriptions is ultimately intractable.
Regarding the claims of the article, I would like to see a lot more supporting evidence. I take generic Adderall (instant release) and have noticed no systematic supply interruptions. Nor have my pharmacist or psychiatrist mentioned any difficulties with availability, although I am used to reviewing the branded vs. generic options and pricing. Mine is manufactured by a firm called Corepharma, which isn't even mentioned in the article. Apparently some people find this version of drug inferior due to side effects or inadequacy of primary effect and prefer not to use it. For me the side effects have been very marginal so I have not bothered to seek out competing products. I presume that for people who are sensitive to a particular ingredient or characteristic the version of the medication they take matters a good deal, but in my own experience it's like preferring a specific flavor of coffee - others don't taste as great as my favorite, but they're hardly undrinkable.
The fact that other brands of the same generic drug go entirely unmentioned in the article makes me question the whole premise. If medication were simply unavailable as a result of manufacturing quotas that would certainly be a bad thing, but from here it sounds like 'it ain't coffee unless it tastes like Starbucks.'