[mistercow]

I don't see a strong argument that "THC" is any better. Everyone knows what THC is.

[protomyth]

You'd be surprised (very surprised - its almost a dihydrogen monoxide thing in reverse), and truly acronyms get more respect.

[reitanqild]

Depends on your definition of everyone. I for one trigger significantly less on THC.

It can also be argued that THC sounds more like a synthesised or refined version consisting of the active ingredients.