RJD, could you elaborate on what program change PrimeKirk could've made that you would find commendable in contrast to what NuKirk did in his change to the program?
The first scene in Wrath of Khan established how cadets were meant to think of the Kobayashi Maru test--via Saavik. Saavik immediately protests to Kirk that the test was unfair. My guess is that even if no cadet has ever beat it, that they enter into the test feeling like it's possible, almost like it's some sort of urban myth. Regardless of cadet-to-cadet chatter in JJ Trek, I think it was like a hazing ritual of sorts in which cadets know they shouldn't "spoil" the ones coming after them about the trick-nature of the test. They may actually enjoy seeing the younger cadets' frustration. Certainly if it were common knowledge, Saavik would not have protested the way she did. However, all officers, having gone through it, know the secret. Kind of like knowing Santa and the tooth-fairy aren't real.
So I think prime Kirk believed that the simulation wasn't a test of character, but a traditional skill-test, just as Saavik did, and that when he rigged the simulator, he didn't want to handicap it to the point where he didn't have to break a sweat. He only wanted to lower the difficulty enough to make it possible to win--but you'd still have to be really good as a fledgling captain. This would be cheating, technically, but really it's just bending the rules out of Kirk's innate sense of fair-play.
That's not what nu Kirk does. Nu Kirk cheats in a Bart Simpson sort of way--to avoid having to exhibit any leadership skills whatsoever. It's a much more egregious rule-breaking, and while it endears the audience to Kirk as some sort of too-cool-for-school "bad boy" it also makes him out to just not be true leadership material.