I think it is because many of us 'old folks' remember the various popular diet pills that would pop up every decade or so. Each time, they were essentially some form of speed/meth. Various derivatives, camoflauged with new names, new cover ingredients.
But in the end, they'd be outlawed because of the meth-like side effects.
I AM NOT SAYING THE PATCHES ARE LIKE THIS. Just saying that we have seen this type of thing play out many times, where eventually we find it is the same chemical derivative, in each new magic energy/diet supplement.
Add to that, cases like that of Capt. Robert MacDonald, who killed his wife and 2 baby girls, and blamed it on a band of hippies who broke into his home. It turns out, Capt. MacDonald had not slept for 2 days, and was kept awake by taking diet pills, while he worked in the emergency room as a doctor:
"Equally, why would a man who had never previously shown aggressive tendencies, known as a loving husband and father, without warning slaughter his own family? The prosecution was never able to construct a convincing motive. Nor was McGinniss. Instead he assembled a large array of character assessments and examples of minor indiscretions to create a portrait of a seemingly normal man who, underneath a carefully composed exterior, was a raging psychopath.
McGinniss discovered that MacDonald had been taking an amphetamine diet pill called Eskatrol and surmised that the drug, and a punishing work schedule, triggered his latent psychopathy. Morris is scathing of McGinniss's account of that February night."
The Fort Bragg murders: is Jeffrey MacDonald innocent?