Linguistics (and being a linguist) is not the same as being a language speaker. A linguist is knowledgeable about word patterns, grammar, tenses, etc., and how they work together to make language communicate effectively.
Most of the responses above deal with people who speak a lot of different languages, but say nothing about the structure of the languages they speak.
I don’t think there is a job for just a linguist. It is in conjunction with something else, for example:
forensic linguistics
historical linguistics
written linguistic patterns
juvenile linguistic patterns and learning
comparative linguistics
So the question really has to turn to – to what field will the students who are studying linguistics today, apply their skills ?