The simple solution to this alleged problem is for QF to buy some enormous closets and have all lounge patrons check their clothes in at the door! But it may create a whole other problem. :shock:
I don't recall having seen hi-viz patrons in any Qantas lounge (certainly not in large numbers, maybe the odd one here or there) and that will be because I don't fly at the right times from the right ports, but I cannot see why their gear should be a problem, as long as it is neat and clean and all the appropriate body bits are covered. As with any other sort of gear worn by other patrons. Naturally there is a 'minimum' standard of dress, and just what that minimum is will vary in different people's minds. I really don't like singlets (on blokes) and think they are probably inappropriate in a lounge or even in flight. But that is just an opinion, and even disliking them does not mean I am trying to force my opinion on others who choose to wear them. I can only recall wearing shorts once on a flight (from JTR-ATH, and just about everyone on the flight was in shorts), but as long as they are neat and clean etc. I don't object to to others wearing them. If people wish to wear thongs in the lounge/on the plane I don't think they're being very practical (quick evacuations onto abnormal terrain for example), but again, no objections.
You would not see me (in normal circumstances, there are exceptions to every rule e.g. the JTR-ATH flight) in any of those items in a lounge or plane - but in hi-viz, why not?