I don't buy the argument that porting the game to the Vita doesn't make business sense.
First, the Vita was developed using an internal architecture that is similar to the PS3 specifically to enable making multi-platform games, or ports, a relatively easy process:
http://www.computerandvideogames.com/288500/sony-ngp-porting-ps3-games-simple-and-quick/#null
http://www.videogamer.com/features/article/how_easy_is_it_to_port_ps3_games_to_vita.html
Next, even though the total sales percentage coming from the Vita version would be lower than the console versions, Vita versions of multi-platform games have managed to sell successfully. Take for example Need for Speed Most Wanted. The game was virtually identical to the PS3 and 360 versions except for some graphical concessions.
Need for Speed Most Wanted is at #5 on the UK chart and has been there for 12 months. Since that time the Vita version has managed to capture 13% of the total sales in the UK, blowing the PC market share out of the water:
http://www.guardian.co.uk/technology/gamesblog/2013/jan/21/top-20-uk-games-week-3
Sonic All-Stars Racing is currently at #13 and the Vita version has captured 9% of total sales.
For comparison sake, look at Skylander's Giants. The 3DS version has captured only 6% of total sales.
On the Wii U Assassin's Creed 3 has a paltry 4% market share and COD:BOPS 2 has a mere 2% market share.
Considering the low development costs of porting the PS3 game to the Vita and the historical evidence indicating the relative strength of Vita version multi-platform sales, it doesn't make sense from a business standpoint to not bring it to the Vita. I guess in a long and round-about way, I am suggesting that it has to be some exclusive licensing deal with Nintendo that is holding them back.