Yes, the beginning third of the movie was wonderful cinema, but soon the filmmakers went over the top using a black hole to get them out of a black hole -- being faithful to the characters and history of Roddenberry's Star Trek. They wanted to be able to rewrite Roddenberry's characters for future sequels, and they copped out by saying they now have an "alternate reality" to begin a clean slate with.
Although it purports to be a prequel with the original characters, the film is not a prequel at all because it doesn't set the stage for the original series. Why didn't they just use new characters like the Enterprise series? Obviously, they wanted to pull in the original series fans hook line and sinker with the addition of Leonard Nimoy. But they violated every Star Trek and science fiction rule to do so. In the past, Star Trek writers were very careful dealing with time travel -- if a timeline was changed, the characters used painstaking measures to set the timeline right. The way these filmmakers did it just didn't make sense.
In fact, the main premise of the movie is flawed. We are told that the main villain, Nero, shoots back "accidentally" in the past after his world his destroyed. Instead of warning his people or preventing the destruction of this planet, he spends his 25 years just wandering around the galaxy waiting for Ambassador Spock's return to exact his "retribution" against someone who tried to save Romulus.
In the beginning, I could believe that Nero just "happened" to run into a ship commanded by Kirk's father and gets him killed; but when the young Kirk just "happens" to run into a cave the old Spock had been hiding in, then just "happens" to run into Scottie on the same planet -- the coincidences are just to ridiculous to believe. And how could the elder Spock meet his younger self in the same time continuum without things going haywire? It just doesn't make sense.
But in everyone's rush to embrace the new Trek, the plot flaws don't seem to matter. The fans say the story doesn't matter; this film has the old characters with good acting. Even that is debatable --Pine plays Jim Kirk as a reckless, spoiled brat who never grows up and gets everything handed to him on a silver platter by virtual of his lineage. Forget the discipline of Star Fleet -- he apparently didn't get any. And both actors who played McCoy and Chekhov tried so hard to emulate the originals they ended up being pathetic parodies in their roles. The exceptions were Zachary Quinto as Spock and John Cho as Sulu. The best actor turned out to be the veteran Bruce Greenwood who played Christopher Pike -- he took charge and was more Kirk-like than the actor who played Kirk.
But we shouldn't be quibbling about this movie because we have Star Trek back, right? Now we can all look forward to the sequel where Spock witnesses his own death while making love to Lt. Uhura.