I think "done to death" is the best phrase I can see here for the Borg.
They were a formidable adversary and worthy of inclusion in their Next Generation episodes. Then Voyager got their hands on them and turned them into little more than the cybernetic laughing stock of the galaxy.
Enterprise came along and, though many may disagree, I thought they had a good Borg storyline – and a good one to finish off the death-warmed-up bots once and for all.
Khan was a good vehicle for exploring how things can run at a parallel but be different in this 'other universe'. And the destruction of Vulcan was effectively used as an explanation for how the Khan storyline came along earlier than it did in the 'real universe'. But how could the destruction of Vulcan possibly be used as an excuse to attract the Borg from the Delta Quadrant so much earlier than they otherwise would have? In galactic terms, the destruction of Vulcan is still only a minor, barely noticeable event.
I know JJ is creating a whole new game, but he still needs to maintain some degree of authenticity by tying in what's going on to the events in the 'real universe'.
We know what the Borg are. We know what they're going to do. We know pretty much everything there is to know about them and we've seen it all. I for one would be decidedly less than excited about going to see another Star Trek film about the Borg.