The only difference is nuKirk's immaturity. He's younger and never had a father figure. He was also thrust from Hicksville townie to Starship commander rather rapidly.
The reason why this part of both films' themes is because it's an on-going character arc.
What's the problem?
I don't think the arc itself is the problem, it's how rapid everything happens in Into Darkness
. Kirk went from starship captain to cadet to first officer and back to starship captain in what seems like a twenty-four hour window.
I know that we don't want to waste time showing inconsequential events between two important events. But we can denote a passage of time without bogging the film down. A simple snarky line about Kirk spending time as the Delta-Vega outpost commander would've shown that some time had past and that he was actually punished for something.
But hindsight is 20/20.