I agree it's spoiled only because it's been revealed that this Kirk is a terrible captain who self-admittedly doesn't know what to do and needs someone in the chair who does know what they're doing and that's not him. That's Spock, apparently (and Trekkies love this movie?).
Some Trekkies like this movie, some do not. As it is with all Trek movies.
I don't know why he gave command to Spock though. I'm not sure what the writers were trying to say. Obviously they want us still to think that Kirk is the right Captain as he had his Captaincy at the end of the movie. Did he really give Spock the conn because he thought he wasn't good enough or thought he was better in the middle of the action. Was he thinking he was compromised or personally reponsible for the situation so he personally had to fix it? I am confused here. What were they trying to say?