Humor it just wild. Yes, I get how it works, but it's still so cool to me sometimes.
Think about it for a second, this is funny and embraceable because it's an accident. If anyone intentionally came up with the phrase "Non-binary Mocha Frappuccino" they'd either be cringe or an asshole. But instead, the accidental existence coupled with the ironic, self-depricating embracement makes it funny.
And of course, if the wrong person repeated this, it wouldn't be funny anymore.