I must say, with all the loopholes, that are in the JJTrek science (flat Black Holes/ Red Matter/ that supernovathingy that wiped the Romulans out, which travels faster than Warpspeed), I never really put much cosideration in explanaitions why certain things happen in those movies. They just do. Like in Star Wars. No one is seriously debating how the Millenium Falcon can travel those distances, with only 4 times lightspeed. That would be around Warp 2.
The interesting question is - is this my universe? There are indications in and around the Movies, that the Prime Timeline has been extinguished and replaced by the new JJTimline. A real life hint to that is, that JJ actually wanted CBS and Paramount to take every bit of merchandising off the market, that was not related to his new movies. Wipe out the old timeline in the movie - wipe out the old timeline in the stores.
So, if time is like a video cassette, then Nero hit the rewind button and recorded a new story over the old tapes. The original time is gone and can never be retrieved.
But if time branches into different quantum realities, the JJ movies are in a different quantum reality, with only Spocks absence noticable in the still existing prime universe. But why should I care about those people in that universe? Star Trek was supposed to play in THIS quantum reality. Why would I care about people having problems in other realities more, than in my own? (I think the "Quantum Mirror" episodes in SG1 made a good point about that)
Fringe, Cloverfield, Lost, Alias and other JJ shows and movies worked, because they were playing in a selfcreated and selfcontained universe. But if one tries to apply rules made for Lost and Fringe to something, that other people have already established a ruleset for since 1964, this is the mess that comes out of it. I for one am still as confused as I was when I read the first entry in this thread. Is this now "MY" Universe/Timeline or not?