I think it's a little more complex, the issue of fans leaving early. First, it's a mid week game. Second, it's an 8 PM tip. Third, the opponent is not a rival, no marquee player, rightly or not, given Arky's road woes, most think the game should be over at half time.
Personally, if I had gone with my wife and child, I'd have left at half time of this one. The kid is in kindergarten and his usual bed time was the tip off time for this game. I live very close to campus, so best of both worlds and I'll miss none of the game because I've got it on the DVR.
Maybe some folks have a long ride home.
Almost everyone has work or school or something.
Let's face the facts. Television drives the start times, in football, television might have us playing on a Thursday for instance. There's a lot of average folks who settle for watching at home because it's been made very inconvenient, all for television.
I'm much more likely to stay for the whole game if tip is an hour earlier, but that's just my own circumstances.
Night games for baseball, for instance, start at 6 PM, with Saturday and Sunday games being in the afternoon. For folks with young ones, that's much more manageable.