What are you talking about? Most of his earnings already are 'at risk'. Geoff has a reduced FAR to obtain access to bonus and equity payments. That is how executive renumeration works.
You can't have a bonus scheme on top of your existing salary.
You're also forgetting that if Qantas goes south, Geoff will be the first to lose his job, not the pilots.
Executive contracts are also negotiated individually - attracting specific pressures. What would happen if pilots negotiated the terms of their employment as individuals? You've already seen what small groups of pilots will do to access career opportunities to the disadvantage of more established groups.
An EBA system is one of protections. There are very few contractual protections for the long-term careers of managers.