4. It Would Fit Both Timelines
As I'm sure you're all plainly aware J.J. decided to reboot Star Trek by going back to the beginning and creating a separate timeline, something which allowed the original to carry on and do whatever it wants with tie-in novels, and having his own to play with as he pleases. It's just that the birth of one James Tiberius Kirk was only the beginning of the original series. Anything that takes place prior to Kirk, Star Trek: Enterprise for example, therefore doesn't have to pick sides. From the point of view of those watching the series, established Star Trek fans can't complain about J.J.'s changes, and new audiences can't get confused. From the point of view of those making it, they don't have to keep double checking which universe they're trying to get their continuity to adhere to, and can concentrate on writing decent stories. This is one of those glorious situations where everyone wins.