Amazing how you can make a simple statement and then have a totally different interpretation placed upon it. Ken, I was simple saying that commuting would be very hard if stuck in economy class for 4-5 hours, prior to your long haul flight.
I also think that a few commuters are risking it a bit by not leaving many options for travel if you don't get on your flight, or your flight goes u/s. When I commuted on the east coast I would allow at least 3 flight options to get me to sydney, but was still paranoid about missing my flight. This is much harder to do on Perth flights as less options and you would end up having to arrive many hours ahead of your departure.
I think commuting to Perth would be ok but probably a requirement to have a nights sleep in the departure time zone prior to departure would be advisable.
But as for displacing paying passengers, you have to wonder how many have actually paid the full fare business class instead of upgrading using points or cash. There has to be a very fine line between people who would have paid full fare but now don't and use the upgrade facility, hence less revenue, versus the money made by upgrading. A false economy if you ask me.