I would not agree that it supports your side of the argument as we are talking specifically about the required course of action in Australia. The ATSB report is a general research document whilst using Australian statistics looked at the various regulations around the world (ie. ICAO, AIP, FAA, JAR, NZ AIP). So you have to read CHAP 7 in it entirety and in context with the rest of the document. The author states that "the rules for carrying fuel to meet weather-related alternate diversion requirements do not apply...Allowances for this risk exist in conservative rules that provide a margin at the planning stage ... This risk may be further mitigated if a pilot monitors a destination’s weather information while en-route, and elects to divert ... if the destination’s weather deteriorates."
My reading of the annexes shows that Australia has the least conservative flight planning requirements. Everyone bar Australia requires an alternate if the weather is worse than VMC below 1300-2000 (state dependant). The FAA even requires two alternates in some situations. In Australia with the SLAM rules the weather can be 180 feet above landing minima and vis down to 2k and still not require an alternate. This would suggest to me that in the context of aviation in Australia the "margin at the planning stage" is significant reduced. However, the ATSB goes on to say that the risk can be further mitigated if the aircraft diverts and that is what this discussion is about and in the Australian context I am in the camp that says you have to divert if you can get to a suitable airfield with the minimum fuel required by your operation. (and forget the ridiculous scenarios suggested such as this happening at the IAF or requiring a 90min diversion over water at night - we are talking about Australia here)