This is irrelevant. If 2k15 was shown with heavily downgraded graphics and said, "well Live's graphics suck too so why should we make our's good?" would you be okay with that? Other games don't matter
The demo's purpose is too showcase the core gameplay experience. The demo would show people that the core gameplay experience has improved over last years. You're making it sound as if this iteration would play the exact same as 2k14 so we should know what it will play like. You can tell in a 5 minute quarter if the CPU still over rotates on defense when a player drives down the middle, you can tell if the CPU still leaves 5 feet between them and their man on the perimeter etc
You're right the excuses
are ridiculous. We have people here that think its egregious to believe someone would like to hear more about how the core gameplay has been improved in detail like they have done in the past as it is as, if not more important than having mocapped cheerleaders.
The demos for 2k have always been 1 quarter, with plays locked, and with the previous years finalists. In your hypothetical situation, why would people be complaining about the length of the game's or simulated stats or access to other features?
That wouldn't make sense. If the demo was great why would people assume the actual game would suck?
I wouldn't be trying the demo to pass the time, I would be playing it too see if the gameplay improved enough for me to buy this years game. How the CPU reacts and plays, the defense etc are things that you see every time you play a game of 2k. You're telling me if you go back and play 1 quarter of NBA 2k12 (multiple times) you wouldn't be able to tell if it was an improvement or not from NBA 2k14 from a core gameplay perspective?