Below are the views of the master expositor of mathematics, Paul Halmos:
Some graduate students now-a-days object to being made to learn to read two languages as a Ph.D. requirement. “Why should we learn about flowers and families and genitives and past principles? — all we want is to read last month’s Paris seminar report.” Some go further:”Who needs German? — for me Fortran (C/C++) is much more relevant.”
Horrors! I am upset and I predict that the result of such anti-linguistic, anti-cultural, anti-intellectual attitudes will lead to a deterioration of international scientific information exchange, and to a lot of bad writing. Every little bit I ever learned about any language was later of help to me as a writer. That is true of the Danish and Portuguese and Russian and Romanian that I learned for specific mathematical reasons, but it is also true of the hint or two of Greek and of Sanskrit that I managed to be exposed to. I have always rued that I was never taught Greek; every ounce of it would have paid off with a pound of linguistic insight. In the course of the years I managed to pick up quite a few Greek root words; my source of them was my shelf of English dictionaries, especially the American Heritage and the second edition of Webster. I feel that I need to look up the etymologies of words before I can use them precisely, and I know (a small matter, but here is where it belongs) that the reason I have no trouble spelling in English is that even a nodding familiarity with other languages makes me aware of where most of the difficult words come from.
To give the devil his due, I admit that substituting FORTRAN for German is only 90% bad, not 100. What it loses in the understanding of culture and mastering the art of communication, it gains in meticulous attention to detail and moving closer to mastering the science of communication. A knowledge of the theory and practice of formal languages might be a help for writing with precision, especially to students whose talents are not mathematical but it is of no help at all for writing with clarity. The distinction is sometimes ignored or even argued away, but that is a sad error — there is all the difference in the world between an exposition that cannot be misunderstood and one that is in fact understood.
(From: I want to be a mathematician: An Automathography: Paul R. Halmos).