Diverting out of Perth can bring its own problems anyway if there is a major issue both both YPKG and YGEL are going to fill up quickly so your alternate may not be available due to ramp congestion. Especially so if a unforecasted wx event happens and everybody gets caught out. What then? I am certainly coming around to the belief that something needs to be put in place legally for Perth. If it all goes bad over there you can run out of options very quickly.
The thing about flying in Australia is that we have very limited options due to a lack of infrastructure and facilities and generally poor and unpredictable ATC. This is usually brought about by archaic rules and procedures. Unlike the rest of the world where you have multiple options everywhere Australia often you have one option and thats it.
Hopefully much is learnt from this incident and maybe the min fuel brigade will consider their options.