Whilst I generally agree with you that these drugs alone don't magically "wake people up", wouldn't you agree that one of the primary functions of government is to ensure social stability?
It would therefore be strange for governments not to try to control substances that had the potential to upset this. No conspiracy is required, just pragmatism.
When the Controlled Substances Act was passed, it included many, many drugs that had been previously criminalized under several different and conflicting laws. That act was an attempt unify drug policy. Nothing can be inferred from that act about why any given drug was or was not criminalized. However the timing of the act is a bit curious, given it happened shortly after a rise in drug use in a class of people who were anti-authoritarian and talked a lot about the cultural effects of drugs.
For your links, here are 2: the first espouses the premise -
