I feel what you're saying and I know what you mean, but from my experiences with 2K's in the past (and the 2K12 demo) this is a different problem from what you suggested. It just seems like the "response" scale is a little messed up or glitched. We can see a routine jumper hit in the first quarter by Ray Allen and we can hear an adequate, real life response from the crowd. But a moment later, Ray Allen can finish an exciting drive to the basket while getting fouled and there will then be a very small response from the crowd.
If the crowd was just generally subdued at all action early in the game that'd be one thing. But if they're responding enthusiastically for 85% of the home team's positive plays, only to go nearly silent for a random 15% of plays (which sometimes include dunks and And-1's) then I believe something is awry.