King Daniel wrote:
That's a handwave, just like the refit in The Motion Picture. What they really did in 1979 was re-imagine Trek's look for a big budget movie. They did the same here.
The interference of Nero in the timeline can only take you so far. As Dennis might so eloquently put it, that's just a fig leaf.
You can see something busting out from behind the fig leaf, especially in the form of the Kelvin.