Do you remember weeks ago we we're discussing the use of -y as a word ending?
I said it was English-y?
Well, I found an example {yes, but I get there in the end}
How about "The Health Food Shop" as opposed to "The Health-y Food Shop"?
Sure I remember! I'm fond of this kind of thing.
Lots of English words have -y as an ending. 'Healthy' is a good example of a word with a -y ending, but it doesn't mean the same thing as 'Health'. Health is a noun. Healthy is an adjective. 'Health Food' is a noun phrase - it's a phrase that people use with a specific meaning. In practical terms, you know that the stuff in a shop with a sign saying "Health Food Shop" will probably be much the same as the stuff in a sign saying "Healthy Food Shop" - but in grammatical terms, there actually is a difference between "Health Food Shop" and "Healthy Food Shop". (Don't get me started on all the shop signs that abuse apostrophes. I swear, when I'm an old lady I'm buying a pot of red paint and I'm going to go and correct all these bloody signs for Fish and Chip's [sic]etc. Drives me batty.)
Either way, though, that particular conversation we all had a while ago about the -y ending wasn't saying that English words didn't have -y endings. (If that was what you thought, I can quite understand your confusion!) IIRC, the article cited was talking about the slang specific to the show - not about textbook use of words, but about the kind of wordplay that's used on Buffy the Vampire Slayer. It claimed that the BtVS slang usage of "much" as a suffix (as in "Slay much!" or "Demonic much!" or "Legal much!") had been replaced by the use of the suffix -y (as in "Slayer-y," "demon-y" or "lawyer-y").
This isn't suggesting that "much" isn't a normal English word, just that it isn't normally used in this pattern. Using it in this pattern is a slang usage associated with BtVS and AtS. I don't know whether it's common in Californian slang, but it isn't the standard grammar usage of the word.
Similarly, adding a -y in this way (i.e. in places that you'd get marked wrong if you did it in an English essay) is a convenient shorthand way of saying "to do with". It's a slang usage on Buffy which is modelled on a pattern in normal English - the pattern in "Healthy", "salty" etc.
Nobody was claiming that the slang was invented out of thin air - it's an adaptation of the way we use English, and that's why it works. "Healthy" is a word. "Demony" isn't - but because it's modelled on a familiar pattern, you still know what it means.
The objection I had to the article was that I think the -y ending is being used slightly differently from the -much ending. (I tried to illustrate it above, but I'm not sure how well.)
In English, lots of adjectives end in 'y'. In our day-to-day speech all of us have particular sorts of slang and speech patterns that differ from standard English - not just the dialect stuff that's the same for one's grandparents, but the specific stuff that's "in" with your peer group - even if it's just a handful of friends. Like the way Buffistas use "foamy". "Foamy" is an ordinary English word. But the slang usage of "foamy" to mean wonderful/desirable/gorgeous is not ordinary. It's specific to us.
Does this make sense?