Yet another Aus vs US interaction it seems...
Rules are rules and when it comes to the airline industry, questioning why or even fighting back is futile. You were inconvenienced for sure, but I'd rather spend 5 minutes waiting for the idiot in front of me to get his bag down to 6kgs than proceed on board in 30 seconds and get hit by a 10kg bag.
Aussies question rules for sure, and even stand up for what is right - but only when there's an avenue for change. A gate lounge or check-in area (which has federal laws to abide by) is probably not one of them. It sounds like most of us here have had exposure to TSA - try convincing *them* that you have a right to, for example, keep your shoes on!