I never pass up on an opportunity to share Simon Pegg's thoughts on the matter - he wrote one of the films, so I think his opinion should carry some weight:
Sure, we experience time as a contiguous series of cascading events but perception and reality aren’t always the same thing. Spock’s incursion from the Prime Universe created a multidimensional reality shift. The rift in space/time created an entirely new reality in all directions, top to bottom, from the Big Bang to the end of everything. As such this reality was, is and always will be subtly different from the Prime Universe. I don’t believe for one second that Gene Roddenberry wouldn’t have loved the idea of an alternate reality (Mirror, Mirror anyone?).
This means, and this is absolutely key, the Kelvin universe can evolve and change in ways that don’t necessarily have to follow the Prime Universe at any point in history, before or after the events of Star Trek ‘09, it can mutate and subvert, it is a playground for the new and the progressive and I know in my heart, that Gene Roddenberry would be proud of us for keeping his ideals alive. Infinite diversity in infinite combinations, this was his dream, that is our dream, it should be everybody’s.