Spock had always been defined primarily in terms of him being the nerdy friend of hero (same goes for McCoy), and yet he should be a protagonist as much as Kirk is. hell, you even have Spock prime telling him that Kirk would "define" him. But I don't see people complaining about Spock and McCoy getting reduced to nothing more than the best friends of hero.
Uhura and Carol have a tiny interaction, actually.
When Kirk and Scotty take Carol to sickbay, Uhura is there trying to help her and whispers something to her (maybe she was trying to comfort her)
tiny but it's there.