Why? The content about those articles is verifiable, any given Buffy episode is clearly notable compared to, say, the "Fourlokotini" article that was submitted to Wikipedia in November 2010, and nobody is gaming Wikipedia to get Buffy content to the top of Google SERPs. What difference does it make if writeups of Buffy articles occupies one article or dozens?

Because it reflects the fact that Wikipedia is currently written by the kind of Comic Book Guy who posts endlessly on Hacker News and edits Wikipedia. We are all Comic Book Guys to some extent when posting on the internet, but there are quite a few important deleted articles that are interesting only to non-Comic Book Guys. Inclusionism is about protecting their contributions from the depredations of rules lawyers who care more about "Notability" than whether a topic is included at all.

Why is any random Buffy episode "clearly" more notable than a cocktail fad? More to the point, why is a Buffy episode more notable than an extant webcomic or a niche programming language or any number of perfectly worthwhile subjects that enthusiasts on Wikipedia merrily purge?

Subjects are notable by dint of being written about in reliable sources, which is something you can say about any Buffy episode and can't say about a cocktail that some guy in Camden made up one weekend and wrote about on Wikipedia as a joke.

'The "notability" argument from Wikipedia Deletionists is fascinating because it basically outsources judgements of significance to major media conglomerates.' -- opendna

You're answering a criticism of Wikipedia's standards by appealing to Wikipedia's standards. Further, you're certainly aware of your painfully obvious cherry-picking.