If computer scientists made similar emotional arguments: Save EBCDIC because diversity. No. Full stop. It's the adherents' of these cultures (speakers' of these languages) duty to compile and/or translate their cultural insights and knowledge. If they fail to do that - good bye, it probably wasn't that important, otherwise the culture or language would have been dominant.
The point is that the existing speakers would like to preserve the language, but might not have resources for doing so. One good thing is that technology allows us right now to do archiving in an easier way. Recording speech, stories, and songs can be done more conveniently. Learning resources can be created in a better way. Problem is that the tools for all this might not be accessible to people living in remote areas if they do wish to preserve their language.