Fame
A person with a background in linguistics who plays his or her cards right could get very famous. Ever heard of Noam Chomsky? If not, have you been living in a cave? If so, does said cave have any interesting primitive writings to study?
Okay, so Noam Chomsky's job title is a little more elaborate than just "linguist," but linguistics is his bread and butter. His meat and potatoes, if you will.
One of Noam Chomsky's linguistics-related claims to fame is his Theory of Universal Grammar. This theory argues that the ability to use grammar is innate in humans. One of the best proofs Chomsky found for his theory is that young kids can come up with and make sense of sentences that they've never heard before—that alone proves that it's more than just imitation that allows us to learn a language.
This is just one example of a linguist who became very famous for his great ideas. Of course, Chomsky's not one to rest on his linguist laurels; he also became famous for his political commentary, leadership, philosophy-related work, and cognitive science studies.
Unfortunately, you probably won't have your own reality show of MTV...if that's the kind of fame you're looking for.