I'm sorry, but I just don't see this is as "can't please the Trekkies" film. I love The Dark Knight. I loved it so much that the first time I saw it in theatres, I had to go back the same day and watch it again. I honestly can't imagine how anyone could compare the two. To use a Trek example, if The Dark Knight is "The City on the Edge of Forever," this film is "The Way to Eden"!
The Meyers films, especially The Undiscovered Country (which I love) were military thrillers. This... again, I just can't understand how the comparison could possibly exist. The Meyers films actually were about the ethics of militarism. This movie is just an excuse to have a big, Texan-drawling, black hat admiral with a big ship to fire at the Enterprise. There's no moral quandary. Okay, well, that's not entirely true. It's presented in a completely black and white way, given the tiniest bit of lip service when it's first introduced, and then completely done away with to make room for more space battles and then never, ever, EVER touched on again.
And I'm right there with you with the philosophy of, "I don't care what changes they make as long as they serve a purpose." I've been screaming that philosophy for the past four years now. I guess the difference is, is that I just don't see them doing that. The changes they have made have been mostly superficial in terms of ramifications and more just to get an acknowledgement out of old-school fans that they actually are doing something "different." But it's to service nothing more than a gimmick. "Oh, look, we blew up Vulcan." "Oh, look, it's the exact death scene from TWOK, word for word, except we reversed the roles and removed all context and consequences." In fact, until I saw this movie, I loved the destruction of Vulcan in the last film. It gave me hope that maybe they'd have the balls to actually do something interesting. But then, as I was watching that death scene in this film, it finally dawned on me that neither one of them means anything or services any kind of STORY. All they can do is throw shock and awe at you, but without any context or themes or meaning, they just fall completely flat.
I should also mentioned that I also went in completely spoiler free. I never saw a single trailer, I didn't follow any of the pre-release stuff. Like you, I thought Khan was going to be in it but never bothered to confirm that. But I actually had high hopes going into this one, that maybe, since they wasted two hours last time in another "nexus" plot that did nothing but justify its own existence, maybe this time they'd actually tell a story. Sadly, in my opinion, I was wrong.