Native speakers of a 'dead' language - a neat trick

Over at his Linlithgow Journal, Stephen is evoking the spirit of the Dead Parrot Sketch in the light of Unesco's startling declaration that, in spite of having several hundred speakers each, Cornish and Manx are both 'dead' languages. I can't quite work out how Stephen feels about this subject, and it seems neither can he! (And someone really ought to gently point out to him that Cornish is not a 'Gaelic' language.) But one of his commenters Matthew Huntbach gets to the crux of the issue, pointing out that the important thing is not how many people speak a language, but whether any of them are native speakers. He concedes the point that there are now native Cornish speakers who were brought up in the language by their parents, but says this doesn't count as it is not a 'natural' transmission - ie. whatever language these people are native speakers of, it isn't authentic Cornish.

Hmmm. In this world of mass immigration there must be plenty of native English speakers around who were taught the language in the home by non-native speakers - they perhaps have a different accent, but are they really speaking a language other than English? My assumption would be that the differences between natively-spoken modern Cornish and long-dead 'Cornish Classic' are not great enough to justify defining them as two separate languages. But even if they were, Unesco should still have noted that - whatever they choose to call it - Cornwall most certainly now has its own living language.