LAME,
What a load of garbage, you do not know what you are talking about! It is NOT std practice to do this in Australia, only company practice.
In fact the tyre and wheel manufacturers have no problem with wheels being stored at working pressure as I have them asked this myself. BA, QF, PX, MH et al all store wheels at working pressures! They are even checked for pressure weekly in the QF system in BNE for example.
This practice was the case many years ago when wheels had a nasty habit of going bang in the night, however it is so long since you have been near any work in this area, you would not be aware of the changes.