Originally Posted by samwiseb
Spock never gives a reason for his objection (presumed, and for that matter it didn't sound like a very strong objection to me). "What are you doing?" It could be anything. It could be practical (they're all about to get sucked into a black hole, and almost did because they wasted time firing torpedoes). It could be political. It could be personal. If it's personal it lacks conviction because of the way he delivers his next line. He never says what he's thinking. If there's nothing there there's nothing there. You fill in the cracks and make up your own reason.
Let's first take a look at the actual text:
KIRK: This is Captain James T. Kirk of the USS Enterprise. Your ship is compromised. Your too close to the singularity to provide assistance, which we will provide.
SPOCK: (to Kirk) Captain, what are you doing?
KIRK: You show them compassion may be the only way to earn peace with Romulus. It's logic, Spock. Thought you'd like that.
SPOCK: No, not really. Not this time.
NERO: (on viewscreen) I would rather suffer the end of Romulus a thousand times. I would rather die in agony than accept assistance from you.
KIRK: You got it. Arm phasers, fire everything we got.
If you read the scene alone your 'anything can be' obfuscation is already wrong. Kirk does provide a political argument. Yet Spock clearly says that he does not give a damn about logic, a word which usually doesn't mean 'logic' but 'common sense' or 'doing an analysis instead of following your gut instinct'. If neither politics nor practical issues matter nor anything logical (read common sensical) matter to Spock it has to be personal.
Now if you read the scene together with the rest of the movie which is about Nero having killed Spock's mother and Spock having serious issues with it plus in particular the most disgusting scene of the movie, i.e. when Sarek tells his son to not suppress his desire for revenge (a remark that would already be utterly immoral among humans while it is suicidal in the case of Vulcans), it becomes crystal clear that Spock has followed the advice of his father.
One has to add though that the scene is just badly written, its purpose is of course to illustrate that Spock and Kirk have learned from each other and it does not intend at all to make a revenge-hungry monster out of Spock. But intentions don't matter and very often the accidental stuff tells you more about the writer than their well-constructed lines. Freudian slips and so on.
I understand that fans of the movie wanna try to rationalize RevengeSpock away but obviously it doesn't work. I find it quite sad that a movie which tried to copy so many things from TWOK missed the part about the self-destructive nature of revenge. That's not at least why I always emphasize that the new movie is brilliant but soulless. They did everything right but missed the essence of a movie they tried to emulate as well as, here I generalize perhaps unfairly, the franchise in general.