Would it have made that much difference to the film if there was some other reason for Spock and Nero to go back in time and split off the NuUniverse? The "Genocide of the Month Club" gets old really fast. Besides, if a body count is what you want there's six billion dead Vulcans in the new movie already.
When was the last time there was genocide in a STAR TREK movie? And what's wrong with blowing up a planet in a science fiction adventure movie? I'm pretty sure that dates back to E. E. Smith at least. And Ming the Merciless probably did it twice a week . . . .
Anyway, we probably don't want to let this thread degenerate into another pointless post-mortem on the new movie.
To get back to the original topic, the new movie is part of STAR TREK continuity now, so I'm sure various authors will get around to dealing with Romulus's destruction--once we get the all-clear to play with stuff from the new movie.
Just like we have with every other STAR TREK movie and tv show . . . .