"Another issue is that an airline may not have its own staff at check-in so those used may be unfamiliar (or unconcerned) about that airline's rules. I had a case last week of two passengers with oversize carry-on bags plus - I kid you not - a full-size backpack each as well. I was the first actual airline employee they were in contact with and that was at the aircraft door.
"Often during boarding we do not see our ground staff until all the customers are on board, by which time the aircraft hold door is closed, making the loading of any bags seized during boarding difficult. A lot of passengers know they have extra bags but are aware they will not be charged extra at the aircraft door as no system is in place for this."
Asked to respond to the outpouring of irritation by Travel readers, an Air NZ spokeswoman - and, to be fair, Air NZ copped less criticism than most airlines - basically blamed passengers for not following the rules.
"Our staff do police the rules and customers carrying obviously overweight or oversize cabin baggage often have it removed at the gate and stowed in the hold and, where practical, customers are directed to weigh cabin baggage in front of our gate staff who also check the dimensions.
"However, the reality of the busy airport environment is that gate staff have a number of safety, security and passenger service roles to perform in a short space of time and there will always be customers who are determined to flout the rules."
If that doesn't sound very encouraging, Thomas AB suggested a tactic frustrated passengers could adopt.
"Whenever I go to my seat and my overhead locker is full, which happens often, I take out some luggage and put it on the floor. If someone from another row claims it, I pass it on to them to store above their row. Most of the time the stewardess intervenes and takes away their luggage to store it somewhere else. Works for me."
But I'll give the last word to Graham CA: "Perhaps Rob Fyfe's parting gift to us passengers would be to have the size, weight and quantity rules enforced at the gate. But don't hold your breath."