I had a similar experience in LAX a few months ago that almost had me abandoning my UA ticket to get a walkup on AS. Fortunately, I was only going LAX-SFO and not all the way to SYD.

To the poster who asked why the people in line didn't grab the people working the podium for the flight to MEX: the UA staff at LAX are experts at getting the heck out of Dodge before any of the countless pax looking for CSR's can corner them. I've never seen an airport with as few GA's and CSR's as I did a few months back at LAX. There were literally 1,000's of pax in Terminal 8, but I could find no more than 5 GA's, all of whom were either boarding a flight or trying to fend off pax who couldn't find a GA. I almost want to join the RCC just to avoid that in the future, but I hate to reward bad behavior with more $$$. The better solution is to send a letter explaining why the business is moving to another airline.