First up, I’m wholly convinced that the loss of any language diminished all of us, because it denies tradition, and further narrows the cultural base.
[You knew that was coming.]
Are all of those “languages”?
Surely some — if not many — are “dialects”. Now, I recall, dimly, as a student being educated — even berated —on the distinction. Hence I stick to the OED definition:
A form or variety of a language which is peculiar to a specific region, esp. one which differs from the standard or literary form of the language in respect of vocabulary, pronunciation, idiom, etc.; (as a mass noun) provincial or rustic speech. Also more generally: a particular language considered in terms of its relationship with the family of languages to which it belongs.
That’s a trifle confused and confusing, so I’ll gloss:
A language is common to a country, a people or a community. It abides by regular grammar and syntax structures. So Aberdeen can communicate with Anglophone Austin, TX, and Alicante with Hispanophone ditto. Differences are mainly usage and dialectical. Just take care over local applications and terminology, such as the myriad implications of wedge, not to mention wedgie.
Two further examples of “contrived languages”
1. Cornish is on that list of “threatened” languages.
Let’s be honest: true Cornish died with Dolly Pentreath of Mousehole in December 1777. It may have lingered on with bilingual speakers, such as John Davey of Zennor (though he, it is alleged, had only a few phrases).
What we have of Cornish today is a reconstruction, one of many variants attempted through the Twentieth Century. It is a construct, has to be heavily policed by self-appointed purists, and lacks much of the vitality of a living, changing language.
I used to illustrate how change in language works by asking students how they listened to music. The answer today might be “on my phone”, which is a further iteration from the previous list of terms, all the way back beyond Edison to the phonautograph of 1857. I’d suggest that the term in current use, along with the technology, changes every decade or so. I’d also hesitate today to use the early-1970s “tranny” (a small transistor radio) without misunderstanding.
2. Then there’s the curious business, back around 1960, of the Irish government’s attempt at a “new dictionary” of Irish.
Unwisely, a bounty was declared for “discovering” vocabulary. As I recall one had to provide a certain number of “words”, and in return one received a ten-bob note (a whole 50p!). The devious types at University College, Dublin, saw a ready way of financing their drinking habits. So it started with “sulfur” and rapidly progressed through dodgy Hibernicising of numerous scientific and technical terms. Sadly, or humorously (depending on your whim), this process persists to the present day — though monetary rewards apply no longer.