With the recent press event revealing the details and launch lineup of the Nintendo Switch, the prolific company's newest console, possible third-party team-ups are all the news. The Switch is a departure from what we've gotten used to in more ways than one, and the extensive third-party support is one of them. Nonetheless, GTA 5 is one game that's unlikely to make the jump.
Of course, absolutely bloody no-one expected to be playing The Elder Scrolls 5: Skyrim on Nintendo's next home/portable hybrid console and here we are. That being said, there are a handful of reasons why Skyrim could be ported and they happen to be similar reasons as to why GTA 5 likely won't be.
See, the gimmick — since most Nintendo consoles are based on a gimmick — this time around is that the Switch can switch (Ha!) from home console to handheld on the fly seamlessly. The console proper is a tablet and a screen, which can be slotted into a docking unit to display the game on a large screen, or can be removed, with two halves of the controller attached to either side to be used as a handheld.

Since it's easier and cheaper to develop such a hybrid with the specs of a portable rather than a home console, the Switch's hardware comes short of the competition. Cramming the power of an Xbox One into a light and thin body like that of the Switch would cost astronomical amounts, not to mention the time required would push the release several years back.
As such, there are only so many games that would run on this thing. Sure, optimization work must be done when porting something to both Xbox One and PS4 due to hardware differences, but in terms of capability, those two are roughly on the same level. The Switch, on the other hand, isn't nearly as powerful.