I have to agree with @GREED
, I'm all for preserving history, it needs to be done. History and heritage are important to a lot of people. But to actively try to protect or revive something that's dwindling out..
It's like not the ecosystem where a species needs to be revived because it plays a vital role. If a language is dieing, let it. Remember it. Celebrate it if you want. But let's not try and revive it just for heritage sake. If a language dies out, there's usually a progressive and logical reason for that, and it shouldn't be categorised as explicitly 'bad'.