Just to restate my supporting position in the avalanche of negativity:
Many of the fan complaints, here and elsewhere, regarding the difference in Kirk's backstory (vs. TOS) pertain to his rapid promotion, brashness, delinquency, etc. To my eyes, this is the purposeful thematic backbone of the film. Trek '09's temporal setup allows the character of Kirk to explore both contemporary and timeless "coming-of-age" themes, specifically in regard to his relationship with his father. The internal conflict of the absent parent fuels Kirk, and is the ultimate thematic hurdle he must reconcile by the film's end.
Can he reclaim an abandoned destiny? Or a destiny that was taken from him as his father was? When Kirk meets Spock Prime, his first question is about his father. In crisis, he offers pertinent information gleaned only from his obsession with his father's disappearance. ("Lightning storm in space.") Led to isolating, rebellious behavior by his perceived slight, his experience with is future crew allows him to transcend his own inner demons and become the man he was meant to be.
Does the film leave him as that man? No. It was a first step. A glimpse. I loved the glimpse, and I love the dramatic structure from which it was experienced. Kirk's journey is an inverse parallel to Spock's and it is only together they can reconcile their individual internal struggles.
Why didn't this land with many Trek fans? Aside from the obvious, it came to me when I was analyzing The Original Series: Trek fans seem to be used to perceiving the stories of Trek in a dialogue-based fashion. Their pallet has been taught, over decades of series, to derive thematic content through almost exclusively textual means. Clearly there are diversions, but on the whole, most Trek installments expound on the theme in some form of dialogue acknowledgment.
Trek '09 simply doesn't deal with thematic issues in the way fans are accustomed. There's very little (read: almost none) recap or blatant explanation of theme in the movie. It is a purely cinematic experience. It is visual storytelling. The character's arcs, while not mentioned outright, are implied through the actions of the characters in the face of the opposition depicted. It is the choices made by the filmmakers out of which a theme can be derived, not dialogue.
This fundamental storytelling difference is alienating certain viewers, and delighting others. It doesn't boil down to the presence of action, or the recasting of actors, because beyond all that, the "drama-and-character-that-converge-to-imply-theme" of Trek is still there.
TL;DR : Not all Trek fans hate the new movie. And that doesn't make them mindless sheep.