Have they ever given a reason why this game is a PlayStation 3 exclusive? As noted on the main page, it's really weird to for it to be a console exclusive with its premise and it's not unreasonable to think it could made for both the Xbox 360 (what with both system generally sharing games) and the Wii U (giving Nintendo a system with specs enough to play it).
The most logical reason is that the game runs on the Phyre Engine, which is a Sony game engine designed to run only on certain Sony consoles and personal computers. Porting the game to other consoles would be very expensive and require a total code rewrite. Even porting it from the PS3 to the PSVita requires work as the console's CP Us interpret code differently.
Compile Heart usually releases games for the PS3 to be released on the 360 about a year later, giving more content. Already happened with Cross Edge as Cross Edge Dashreleased only in Japan.
The regular Wii should be able to handle it too. The PS2 could handle KH, and since the PS2 and Gamecube are roughly equally powerful (and the Wii is a slightly more powerful gamecube) there shouldn't be any reason why this can't be ported to Wii besides favoritism against the Wii (and Xbox if they don't port it to that). Also, there is that the Wii could handle Legend of Zelda: Twilight Princess (correct me if I'm wrong about the favoritism...)
Different console makers have different qualifications for developers and different editorial guidelines for video game themes. Some console makers prefer established businesses staffed by experienced professionals, some require developers of download games to work with established publishers of disc games, and some may fear backlash from gamers over anvilicious delivery of the Digital Piracy Is Evilaesop. In fact, console makers' shunning of amateurs and startups is what leads to (non-pirate) use of things like R4 and CFW in the first place.
It should be noted that the 360 has basically no market share in Japan, so it's rare to actually see games by any Japanese developer ported to it.
How the bloody hell did Hyperdimension Neptunia V get a T for Teen rating when the rape subtext is EVERYWHERE when Iris Heart is around?
Maybe it's because it didn't involve a pedophile (CFW Trick, we're looking at you), and umm... a mass murder ending?
Specifically related to Neptunia Re;Birth 1 in this case: Why is it that when half the CPU's powers were copied, they lose them, while the other half get to keep them?
Copying and outright taking the powers were two different things. Arfoire can apparently completely take a goddess's power, and seemingly prefers this since the original seems to be better, but will simply copy it instead if she doesn't have a good opportunity (note that she intends to outright strip all of them of power, but after being beaten in several battles has to resort to a quick copying), as copying appears to be easier than taking entirely. Possibly a metaphor for how pirates would prefer a (stolen) official copy of a game, but will settle for a pirated copy in a pinch, even if it is rather...malfunctional, as the goddess clones (and many pirated games) are. Extend this to the fact that the "pirated" goddess copies were confused with the real thing, resulting in Mis-blamed, and the metaphor just keeps going...
Anybody else find it odd how Compile Heart and Idea Factory didn't try to contact Nintendo about releasing MegaTagmension Blanc + Neptune vs. Zombies for the 3DS? It's focused on the Nintendo CPU, it has online multiplayer...