The Vita has the hardware and it has the games to justify the price it currently has. Sony doesn't have the money for major advertising.
If there was a marketing campaign it would be doing much better than it is right now. But I would also like to point out that this thread was created to compare the 3DS to the Vita at the $250 price point. Wasn't saying anything about either system being bad or the future being grim.
I'm sure the Vita is profitable for Sony and that is the focus for the entire company right now.