Zappa was late to the party on this, anyhow. People had been obsessing over the Shaggs for probably a decade before he heard them on whatever radio show it was.
I used to have a boss ho once owned three sealed Shaggs records and had a custom leather jacket with the cover of Philosophy of the World painted on the back, and all of that stuff predated the Zappa hype, just for example.
I've been able to sing pretty much their entire recorded output from memory since I was 14, and PHilosophy of he World has informed pretty much every artistic project I've done since then, however dubious those may be.
But I do understand why a lot of people still don't get it.