In the original Trek series she was the ship's radio operator, which mapped to a pretty specific set of skills in the real military of the time. In the resurrected version she is a trained and highly skilled linguist.
...Also, she's young enough that she could be a completely different person in the two universes (that is, she was conceived and born after Nero started screwing up the family histories of certain Starfleet personnel). At least Chekov is a different person in the two movies - while by the same token, Kirk, McCoy, Spock, Scotty and Pike are their TOS selves, biologically.
I vastly prefer the idea that the TOS Uhura was a skilled communications technician with little or no knowledge of languages, while the STXI Uhura was a skilled linguist, possibly (but probably not) with little knowledge of communications technology. After all, that is a good match to TOS and the TOS movies where Uhura didn't speak Klingon, or any other foreign language besides English.
Why should we contradict what we saw and heard on the matter? We aren't insisting that Scotty be a skilled linguist, or that Chekov be, or that Spock be. In theory, all of them might "have" to be, as they deal with alien technologies a lot. In practice, we see them do quite well without such skills. And we see Uhura do well without those skills.
Is Uhura somehow unworthy of the heroine position if she doesn't have secret superpowers?