Sheesh Guv, when are you going to get it? Most people on here with any knowledge of the airline industry, especially us 'systems monitors' as you like to call pilots, have no respect for you or your self promoting bovine excretia. You singularly fail to realise that your delusions of supposed knowledge about the job only come back to haunt you and prove to the rest of us that you are nothing but a fraud and a pilot groupie who uses Pprune as a laxative for your own mental constipation.
Never mind taking the bait, you fail to realise that the only people you manage to impress, and then only for a short while, are naive wannabes who are easily led by your fraudulent claims of being an airline exec and former pilot. If you or any of your camp followers need proof that you are so full of your own self importance and your ignorance of issues that are necessary for us 'systems monitors' to be aware of I will try and explain a few basic for you:
You asked "And, if your position is that dumping fuel is a waste of time and money - why is it that airliners have dump systems?" If you had any insight into the job that you are always so quick to spout off about you would know that a fuel dump system, if one is available, is to allow an aircraft to reduce the total amount of fuel in a particular tank... if time and circumstances permit it.
On the Boeing 767-300 for example, The capacity of the useable fuel in the tanks is 18,450Kg in each wing tank and 36,500Kg in the center tank. The total useable fuel capacity is 73,400Kg. When the 767-300 is fueled, the wing tanks must be filled first and then the remaining fuel is put in the center tank. Fuel is used first from the center tank and then from the wing tanks.
On this aircraft the fuel dump only does so from the center tank and then at a maximum rate of 1,200Kg a minute. Use your spare brain capacity to work out how long it would take to dump a full centre tank (rare as the payload would have to be substantially reduced). Don't worry, I'll do it for you because you are no doubt looking up some numbers to try and dazzle us all with your knowledge, NOT. 30 minutes to dump a full center tank and you would still have 36,900Kg in the wings which you CANT dump!
So you see, if you have a serious problem that mandates getting the plane back on the ground in a hurry, not sure what because I am only a system monitor, then you may have to hang around for 30 minutes just dumping what you can and then still have to try and land with over 35 tons of fuel still in the wings! Oh hang on. I have just thought of a problem where I may want to get the plane on the ground in a hurry without dumping fuel, an engine fire that will not extinguish or perhaps smoke in the cabin or cockpit. Those are the first two that spring immediately to mind. Guv, can you in your vast wisdom think of any others? I doubt it because you are such a Walter Mitty type that most of us on here do not fall for your bull.
The 767-300 can land above max landing weight up to and including max certified weight. It just means that it would require an overweight landing inspection after the event. Much cheaper option than us 'system monitors' losing it because we are so traumatised by the Guvs predictions about how we really are nothing more than overpaid prima donnas that just jump out of our seats in a panic, wringing our hands in grief and go sit in a corner blubbering away because we are not capable of dealing with a particular situation.
Of course if the problem is one where you still need to get back on the ground but there is no immediate danger then you would be able to go somewhere and reduce the weight but at no time does it guarantee that you will get below the max landing weight of the aircraft, just that you will be at a lower weight which gives you slower manouvering speeds and the ability to use less landing distance.
So you see Mr know-it-all Guv, SOME airliners have fuel dump systems but for someone like you who has such vast experience in this industry should know that they are not the panacea that you imagine it to be, especially if you have to get your plane on the ground within a few minutes. And if you thought that a fuel dump system could empty ALL the fuel tanks then I am glad you don't have any input on an engineering or design forum.
Finally you said "I'm not trying to score points here - I'm genuinely puzzled as to why Airbus think they don't need something everyone else does!" Frankly, I believe you ARE trying to score points as you do in EVERY one of your pathetic posts that contain one or more of your assumed gems of wisdom but which in reality only contain only the brown stuff that comes out of the south end of a northbound bull. From what has been stated, the fuel dump is a customer option on the Airbus A330. On the 757 it is not available and on the 767-300 it only dumps the center tank anyway. So your high and mighty tone as to why Airbus THINK they dont need something that everyone else does just proves to me and the vast majority of 'systems monitors' that you are in great danger of exploding if you do not use your own 'bovine excretion dump' with such frequency on thses forums.
Perhaps it is about time that the Guv found himrself somewhere else, where he can try and impress a few gullible types and left the rest of us in peace. If the mention in a different post about a few of his creditors seriously trying to find him is true then maybe once the course of the law and justice has taken its course we will all get some peace!