Obviously only Nikon knows for certain, but very few Nikon primes anywhere near that focal length come with VR. There's an 85mm and the 105mm, but that's it.
I have always assumed VR must add to the overall cost, weight and complexity of a lens which may be enough to preclude it's inclusion.
Depending on how important VR is to you, there's always the "slightly" heavier, "slightly" more expensive Sigma Art series 50mm to consider.
When one does not know the answer to a question the answer i always money. It would increase the cost and size and is probably not necessary for a lens that is easy to hold steady.
Interesting, I don't think I would even have had that as a consideration for a 50mm lens. I guess it would be handy if hand-holding in very low light. Anyway, it is cost for sure.
Probably because of the size increase that VR would need to function properly. Prime lenses are Fast, Small and Light and, for some, not expensive. I think VR in a nifty 50 would not meet all these criterions.
There's probably at least 4 or 5 reasons why Nikon doesn't put VR on their smaller primes... The cost benefit just isn't there... VR helps in low-light, but most of the smaller focal length primes are already either f1.8 or f1.4... hand held motion is also less pronounced at the under 100mm range than at the 200mm Plus range... adding VR adds lens design complexity which seems to translate to "less sharp"