"specialist languages"?
It may shock some...but English is not the most-spoken language....
Specialist language is a language which is spoken by a particular group. You can find English speakers everywhere but not Mandarin's. That is why to understand it, you will have to wait for a person who will come and decode it for you. Until then you will have to wait.
Don't say, you will use google translate or any web translator, what if you get a hand written billet-doux in some unknown language... Hey don't smile that's not goin to happen that's only if!!!!!!!..... How would you type...
English is the only global language. It might have lesser number of native apeakers but it is most wisely used.
'Specialist languages hinder communication.'
Source: Barriers in Communication.