Duke has an 11.5 billion dollar endowment. They can sacrifice some basketball revenue. Not to mention their basketball apparel contract probably dwarfs ours.
Seems like the other side of that endowment would mean they could easily afford a new arena, but have chosen not to go that route. Maybe they have chosen substance over flash, which we always also seem to do given the choice. Not saying it's necessarily the right choice, but I could easily see the higher ups deciding the return on that investment wasn't worth $150M (or whatever), especially back in the Ray-Howland era when this decision was made.
As I've said before, I'm not sure recruits care so much what the arena looks like, or the comfort of the fans. Many teams with a lot worse arenas than us seem to recruit just fine. Besides Cameron Indoor, Allen Fieldhouse hasn't been renovated in over 20 years. Gonzaga plays in a 6,000 seat arena. Michigan State had a $50M reno in 2016, but that only added a weight room, some hall of fame room, and other cosmetics. The list is long. I'm just saying, this new facelift shouldn't set us back.
Hopefully Jans will get us to the promised land and we have a huge influx of contributors so we get to rethink our decision. But then that would be ironic if we start winning and it had nothing to do with whether the Hump got a facelift or a complete demolition and build back.