One major difference (and perhaps a helpful one for cuisine, if not for language) is that since languages are communications tools (possibly among other cultural purposes; but definitely communication) network effects are a killer. A language that very few people speak isn’t wildly useful, will have slim or nonexistent native or available-in-translation literature and media, can be used to communicate with very few people (who tend not to be the movers and shakers in terms of things like ‘economic opportunity’). It makes linguists sad, and being among the last speakers of a given language must be unbelievably depressing; but the closer to extinction a language is, the less able it is to resist on its own merits as a language and the more it has to rely on people with linguistic, cultural, or other motivations for reviving it.
With something like cuisine, by contrast, it can be very difficult to stop the tectonic shifts in ‘what does 80% of the country have at lunch every day?’; but people seem to adore novelty and ‘authenticity’ at least on occasion and more obscure = more novel = cooler.
This isn’t necessarily much comfort to the ‘preservation means ossification just as it was!’ school, since that desire for novelty frequently turns into assorted ‘fusion’ cuisines and cuisine modifications; but there isn’t nearly the same degree of self-perpetuating doomedness, since rarer cuisines aren’t less useful than more common ones.
