You're making a dishonest argument here. ... Like I said, it's pointless to single out specific inconsistencies as evidence for the thesis that Spock Prime comes from a different reality, because Star Trek has always been full of inconsistencies and impossibilities.
You're getting bogged down in the details. I admitted that nothing I offered up was conclusive, because the film itself makes no comment on Spock's timeline of origin. None of the potential inconsistencies are meant to serve as proof, but elements that can be drawn in to support the hypothesis.
I remember back before the first post-finale ENT book came out, and there was a lot of speculation about what was gonna happen. Some people were saying that Pocket should just bring back Trip, with the reasoning that TATV was just a holo-program, and so it needn't have happened exactly that way.
Other people, including some authors, IIRC, replied very adamantly that such a thing would never happen, because Trip's death was what happened onscreen, and the showrunners' intent was for that to be exactly what did historically happen.
Yup, and it's been mentioned before. A double standard of their own, insisting that what was seen is immutable when the book line performed such a radical rewriting of a series finale--changing even including the year the events took place!--and with far more evidence onscreen for the original intent; as opposed to Abrams' Product, which, as repeatedly pointed out, never pronounces itself on the issue. "Old Spock is the previous Spock" is an assumption; fanon, not canon.
Occam's razor
supports my position. To link Abrams' Product to the 'Primeverse' requires jumping through all those hoops and creating all those rationalizations, like those I suggested as examples, or
Christopher's theory regarding the temporal mechanics. The assumption makes the scenario overly-complicated. But all those problems fall away with the simple invocation--"alternate universe".
That's the emotional crux of that whole plotline, not any nitpicky concerns over the art direction or whatever. ... Why else were we supposed to get all nostalgic and misty-eyed about him being reunited with Kirk?
Emotional crux? Nostalgic and misty-eyed?

The only thing that scene made me feel was nauseated. Much like the rest of the film.
If you want to pretend that Abrams' Product had emotional resonance, then it shouldn't make a difference where Old Spock comes from, because (a) whoever
Spock is, it's not our
Kirk; and (b) in the alternate universe scenario, Old Spock remains Kirk's friend, as he explicitely states.
Why are some people so determined to prove that the new movie is somehow invalid, illegitmate, and unconnected to the "real" STAR TREK--even to the point of deliberately misunderstanding the movie just to prove that Nimoy's character wasn't the real Spock?
Because, in this case, the premise allows us to. And it's not a misunderstanding because the scenario put forward was never in the movie. It's an alternate interpretation.
Besides, the look is irrelevant.
The look isn't irrelevant; in-universe, it implies the work of no small number of Starfleet and/or civilian designers, engineers, etc. If the look is different, then something must have happened in-universe such that one set of designs were favoured over another.
It's a Spock. But only it's quantum spin resonance technobable tag thing can tell you from which universe it's a Spock from!

My point was more if author's wanted to ignore the destruction of Romulus and still write stories set in the prime universe, there was nothing specific in the movie that made it impossible.
Precisely. That's the whole point. The premise is set up in such a way that it is easily disconnected from the extent franchise--as, indeed, it was never connected in the first place!
But, as Christopher also pointed out, we don't make a point of finding ingenious ways to ignore the movies and tv shows our books are based on . . . .
That would just be rude.
And, as I keep pointing out, it's happened before, most notably with "These Are the Voyages..." and the ENT-R. The opportunity and precedant exist.
Fictitiously yours, Trent Roman