Crystal S was initially seeded into middle school populations via Radiopsychic Broadcasting (RPB), one of the first public uses of Radiopsychic Facsimile - the transmission of visual imagery into the mind of a recipient.
Cool S is extremely simple in a logical sense (nine or so lines in a symmetrical pattern, the word "Cool"), leading to a low cognitive barrier to adaptation. This meant high adaptability to new hosts and effortless cultural spread.
Just Rewrite this entire part:
Of course it wasn't publicly called Cool S until cultural retrospectives like Soimon Boyd's Do You Remember that COOL Frickin' Letter S from the 90s? It's So Rad! deemed it so, but that eventual etymology dovetailed neatly (and debatably coincidentally) into the description used by the Radiopsychic Division [Rename] itself.
Let me ret-con that: Soimon Boyd glows. He has addressed this in I Am NOT a Heckin' GLOWIE!!!, but most are unconvinced.
Not sure yet.