Sounds fairly normal to me.
Passengers have been re-accommodated with delays in some cases and in others at decent hotels.
Aeroplanes break - and in this day and age airlines can't afford to carry operational spares.
This sort of stuff is becoming more visible because of Facebook, Twitter and the like but has been there for years.
All airlines make themselves a potential victim of computer failure these days as nobody seems able to pull out a manual load and trim sheet and a seat sticker sheet but to have people able to do this would require training and for people to take responsibility which would cost all of the airlines money.
Aint gonna happen!
Virgin is no better or worse than QF but at least both still take the ball and take care of passengers when something goes U/S.
Best all
EWL