Yes, Manfred - l quite agree that our approach may sometimes be a factor to the attitude of a customer .... but I think here we are discussing the numerous times when we have to bear the brunt of outrage when all we have done is be civil, and have probably been asked by the customer to perform a task that is quite impossible at that exact time.!!!!
Sadly, a minority of customers think that their airline ticket has actually bought them the whole airline.
I have witnessed customers going ballistic because a colleague could not "magic up" a freshly brewed cup of tea from the rubbish cart they were manouevering down the aisle, have an armful of trays and are physically unable to take the empty glass being thrust at them in the aisle, or are expected to get a 15kg wheelie bag that has been "smuggled" on board and the overhead lockers are already full of them !!!!!!
I am not condoning that smart or sarchastic retorts should be administered in every case - but l would hazard a guess that most of us, whatever job we do, have said the wrong thing at the wrong time.
As an aside, my favourite quote (which sadly, I never witnessed) was made to a gentleman who, when told that his handbaggage was far too big for the locker and should be checked-in to the hold, suggested that the female flight attendant "shove it up her a**e". Calmly, and politely, she knelt down beside the pax, and replied "I'd love to sir, but I already have one up there from the inbound flight"