The cut scene in Trek '09 where he apologizes to the Gaila-lookalike would have done a lot to make him seem to grow, but the fact JJ cut that scene out says it all about his low-priority he is on character-development.
That scene made him look racist in the "they all look alike to me" vein. The scene was wisely cut from the film.
If it's OK to allow Kirk to look like a chauvanist for the sake of showing him "grow", why not some accidental passive racism while he's otherwise trying to apologize for being a wham-bam womanizer?
It's not just like one moment he's going to be an immature brat, full of flaws, and the next moment he's a paragon of virtue. It takes multiple steps forward, and the scene with the lookalike could have been one of them. That it would have been a lightning-rod for criticism is probably true, but then so has this scene in question with Marcus. If JJ and company are the serious auteurs that some are claiming he is, then why not stick to your guns for the sake of artistic purity and leave it in? Personally, I think that scene was cut out for the same reason the flashback with him and his guardian (Uncle?) was cut-out. To favor fast-pace and action above character. My speculation as to their motives is at least as valid as those who have read all this added-depth into the Marcus flesh-flash.