Until they ask each passenger to step on the scales as well, this kg penny pinching is going too far, IMO.
Qantas/Jestar have lost my business to Virgin on two occasions recently despite being a longstanding QFF member mostly due to their misleading pricing policy on their website.
Qantas advertising their cheapest fare as $x and then hand-balling it on to Jestar for them to add all their extra fees to the headline price does not make me feel happy about using them.