I made a larger post on the outside but I want to ramble too!
I think what makes video games fun is really different for many people. I enjoy 48 minute games where role players may decide who wins or loses. I enjoy controlling a 32 team association. I enjoy always playing as a low ranked team for a challenge against the CPU. I tweak and edit the game to make it as basketbally as I can.
For me fun is relative to control. I don't see myself playing video games as much as controlling an NBA game from the perspective of one team. The challenge isn't whether I clicked the right button combo but whether I should have posted up David West instead of running pick n roll with Paul George. And the very fact when I play 2k13 that I am thinking solely in terms of basketball strategy not video game strategy means this game is very realistic to me.
When I look back at all the games made from NBA Live 2000 onward the progression has been great. NBA 2k13 reached the watermark for me that this game is realistic enough. The other basketball game I have fun playing is College Hoops 2k8. I have fun because I have an insane amount of control (for a console game) on the game however the game doesn't play anything close to realistic college basketball (I would love if they applied 2k13's feel to a new college hoops game....its sad I literally dream about this at night).
I often find myself in the minority with video game players. I am 32 and my wheelhouse for video games outside of sports comes from games like Baldurs Gate, Neverwinternights, Dragon Age.....what all those games had was a great modding community to make the games what we wanted. And the debate about realism was always there as well. The comparison to sim players was hardcore D&D rule guys vs. hack n slash etc.... My point on this tangent is that realism is very subjective.
A few things I would like to see from my realism perspective.
Different player models. Editable arms, legs, bellys, shoulders etc.....
Unique player short sizes, not team based (the John Stockton rule)
Off hand skill attributes with animation packages based off this skill (layups and dunks)
Palm the ball attribute with animation packages based off that skill
Refine the running/hustle attributes to actually represent players who stand and watch alot versus those hustle every play
Expand the game to include a generic integrated college league and world basketball leagues (This to me is the promise of next gen. More power should equal deeper games with multiple league/schedule/scenarios. How great would it be to be in association and you can pop over the the college basketball schedule page and play a game with next years potential draft picks. Just import College Hoops 2k8 code figure out how to integrate it with a 2k association and you would have awesome! I fully expect Leftos to make this happen
)
Honestly if all they did was figure out a way to integrate College Hoops with the NBA2k I think that would push realism over the charts. Draft classes are nice but how about full integration of college and world leagues into the 2k basketball brand. I know this would be off the court realism but this would be my push.