Languages, I would place very highly. In terms of career prospects they are essentially infinite. Any international company needs translators, advisors, project managers, sales reps that can speak the local lingo. From pharmaceuticals to banking to aviation, there's always a place for a linguist.
As with language skills, say, Mandarin, Russian you can bridge the gaps between countries, you can open doors to other cultures - not only is that rewarding personally, there is money to be made there.
To address the STEM people, yes English is the accepted language of science, but CERN is in Switzerland and if you're lucky enough to work there, you'll be staying in that country...
Common courtesy people, less that 6% of the world speak English as their first language. That's 94% of the world that English speakers require a foreign language to meaningfully access (FYI there's high paying jobs going in those parts too).
It's different and varied, you speak to new a cornocopia of people and improve your skills constantly. Not just for the language:
e.g: If your job is to reach an agreement with a foreign company to work in partnership (such as oil drillers in the middle east) then you need to use many parts of your brain. 'Languages' is but an aspect, you can do much more.
Not only all that...travel! If you speak French, your work in 'languages' could take you to Senegal, Canada, Haiti, Belgium, maybe even France ("ah, Paris!").
I think why most have placed it in the lower section is because A) Many overlook it as they themselves are not multilingual, B) Languages take time and effort to learn, and C) A degree is not required to learn a language...however is desirable. And, contrary to popular belief, a hard qualification to get a first in.
I can speak Swedish, Danish, Norwegian, English, and French - learned in that order. I am only 17. The more you learn languages the better and faster you get with each one. It's part science, part art.
En plus mes amis, I extracted this from an article:
"To find and keep valuable bilingual workers, employers are willing to pay big. On average, bilingual pay differentials range between 5 and 20 percent per hour more than the position's base rate, according to Salary.com.
Thirty-one percent of executives speak two languages, according to a poll of 12,562 visitors to the Korn/Ferry International Web site. An additional 20 percent speak three languages, 9 percent speak four languages and 4 percent speak more than four."
So guys, sorry for length, but I feel that languages do not get enough recognition. And remember this: take your own language for granted sure, but 'other-languaged' people do not!