Qantas have tried to change the ratio before. They desperately want to cut back the crew complements regardless of safety and service. All domestic aircraft now operate on the minumum legal number. With talk of all economy 767 a/c for "leisure destinations" of course they want it changed to only 6 crew for 250 -299 y/c pax. The pax now don't know the overwing exits on all 737-300/400's are unmanned, so I guess having a door exit without crew is not an issue!
Sydgirl,
Variable crewing was looked at several years ago. Too complex for QF to manage. Their option was just to remove the crew off the a/c type permanently.