The introduction of RVSM in Australian airspace has produced a parcel of "convenient" levels above F290 that were not an option in prior times. The natural tendency has been to make use of these levels as desired, consigning the 'non-standard' aspect to the 'doesn't matter' bin.
Over the North Atlantic, and similar, RVSM has a real needed purpose. In Australia it is a luxury. (but, dare I say, world's best practice?)