I have a few issues with such a sentiment:
From the article Valve's policy is "was not under any obligation to repair, replace or provide a refund for a game where the consumer had not contacted and attempted to resolve the problem with the computer game developer". Whereas the assertion by ACCC states "It is a breach of the Australian Consumer Law for businesses to state that they do not give refunds under any circumstances, including for gifts and during sale".
I don't see a real issue here, Valve are essentially saying you at least need to make contact with the developer of the game first and attempt to get your issue rectified before they will step in (the "had not contacted and attempted to resolve the problem with the computer game developer" part), maybe I'm speaking a different english than Australia (or words mean different things over there) but this seems quite reasonable. If I buy something from a third party via either amazon / ebay and have an issue with it I'm pretty much required to at least speak to the supplier (through their messaging system so there is a record) before amazon / ebay get involved.
Also most of the "broken" games on steam have a common tag, "Early Access". I'm guessing if this lawsuit goes through the entire section will get locked off to Australia. Which brings up a interesting question, how well does Australian law and crowd funding get along?