I still want to see more NTs on par 64+ courses. The PHX courses leave me a little underwhelmed despite the wind, rain, and the long water carries. I know it is hard because you have to be able to accomodate all divisions. But at some point, I'd like to see the best players play the hardest courses only, and only in the open division. I suppose my wish will be granted for this year's worlds.
At NTs, there's no reason to accommodate any divisions other than MPO and FPO since those are the only required divisions at those events. So that shouldn't be an excuse, IMO. It's nice that most NTs offer age-protected divisions or run a concurrent amateur event, but it's not at all necessary.
What I think you're getting at is to have these events on courses where the SSA is 64+, not the par. Par can be anything we want it to be. You could call Fountain Hills a par 90 if you wanted, but it wouldn't make it any more challenging. I think having the biggest tournaments on the most challenging courses is a great ideal to strive for, but practically speaking, it's something that is still relatively difficult to pull off.
At this point in the sport's evolution, the primary factor in creating the biggest events is not having a challenging course, it's having the staff to put everything together. A great tournament staff can pull off a great event on any course, meanwhile a great course can't host a great event without a great staff doing all the work.