Going to a doctor with falsified concerns of a deficit in attention in an effort to get a prescription with no intention of using it on a regular basis to treat ADD or ADHD, but rather to use it explicitly for enhancing one's ability to study or perform. It would be difficult to prove this intent, but hiding behind the weak justification of "oh, well they have a prescription now, so it's okay" ignores the deontological question of is drug abuse inherently bad? This is true with all prescribed drugs, not just adderall. It would be foolish to think that all doctors are compitent at their job (though the overwhelming majority certainly are) and even more foolish to think that all patients have good, truthful intentions.
Chiefly, my concern lies with those who abuse without prescription. Certainly someone could, as the OP puts it, "[flock] to local shrinks seeking Adderall" and that may be a more kosher way of obtaining it. But there are plenty who will buy it illegally all the same. It's worse if they then lie about having a prescription.
One day I may very well be in a position to decide who is and who is not faking. In the mean time I am entitled to my opinion however foolish, uninformed, or misguided. In all honesty; it's not your business to tell others whether they are allowed to think critically about ethical decisions.