Callistemon language shouldn't just be viewed for its usefulness.
For decades people have been saying 'what use is Maori, you can't use it outside New Zealand?'
That's a very odd way of looking at it (in my opinion) and now, when its use is becoming more prevalent (and needed), there are calls to make Maori available in all schools (not compulsory as the press would have you believe, just available). It has long been an official language, though largely ignored. 
A language is a treasure and a beauty in itself.
Look how much the language you speak at home, tells you what sort of people you came from and about your culture.
English, is actually a very negative language due (it is said) to our inate reserve.
Someone will say, 'I don't suppose you have any orange juice have you?'
A slightly diffident request which clearly expects a negative response, instead of asking outright with the assumption of a positive reply. English is full of such phrases.
"That's not to say your suggestions are not without merit."
"We went sailing and the experience was not altogether unpleasant."
In Maori, to feel 'mokemoke' is loosely translated into English as 'lonely' but it is far deeper than that.
Kei te mokomoke au means I feel abandoned, as if I have lost a lifelong, much loved companion; a depth of loneliness and despair we can't explain in any English way.
So learn a language for its history, its excitement and stimulation, its beauty and challenge to the senses, not just because it may be of use.
