i did a quick review of the thread and couldn't see anyone who has suggested what you are saying, so its a straw man argument, I suggest. For my own part, I've suggested that QF, operating these ultra long haul routes (and there are more coming) may need to build some fat into their system to mitigate the effects of IRROPs. Yes, this fat would be a direct cost, as by definition more than they optimally need, so it would be a straight commercial decision of bearing the additional costs in mitigation of possible need. You certainly don't need a spare plane sitting in a shed. You might do better by having, say one additional plane more than 'optimal'; it would be working but the total fleet time-on-the-ground would increase a bit. Same with crew - you might have some extra crew in the rosters. I don't know the technicalities or how it might work - its just a suggestion that if possible, the severe knock-on effects might be mitigated to some extent.
Personally, I always book at least a day's buffer when flying long haul and where I'm connecting to something important, or a flight on a different PNR, to allow for cancellation and delays. In an up-coming trip to Russia, that's adding 2 nights to a trip that's only strictly 7 nights, so its expensive 'insurance'. But if I was flying QF9 or 10, I'd probably be looking at 2 nights buffer, judging by the effect this recent event has had. That gets too expensive, so that's a reason I'd never fly that route as is. Time will tell if many are of a similar mind.