Cost.. but in particular the crazy disconnect between a red e-deal and a flexi. Take BNE-SYD... Lots of flights available at $150 for a red e-deal or $633 for a flexi. More than quadruple for what? Not much.In what way? Cost?
Yes, I realise a lot of huge corporates are getting big discounts on corporate fares. But even then, most companies don't allow staff to book flexi fares unless certain conditions apply (eg. reasonable expectation a meeting will finish early, or it's a Friday afternoon, etc).
For this Platinum One who is in charge of travel for staff, the VA changes are very appealing - greater flexibility for an extra $50 or so. I think it will be very tempting for a lot of people and companies.