comeflywithme
It's not so much that I expect to get what I haven't paid for, rather that I am confused about the different policies across airlines. As I said, I have been given free upgrades by BA a number of times, mostly at the check-in gate, and so I can only conclude that it is BA policy to allow it under certain circumstances. I am interested to find out what the policy is at other airlines, and what rationale is given for or against the policy.
I must say, I don't understand your suggestion that if all airlines did it, they would go out of business. If they have a flight with spare seats and extra food, then it is costing them absolutely zilch extra to accommodate an upgrade (except maybe a few glasses of wine). As I say, I still don't think I understand why it is that certain airlines don't allow it.
I'm not saying that everyone who dresses nicely deserves an upgrade. Simply that if there is a genuine reason for the request, they are going to fit in with the cabin without disturbing the other pax who have paid full fare, and they can be accommodated without extra expense to the airline, why shouldn't airlines allow it?
One of the answers I was trying to elicit was whether some airlines have strict policies against it. From what Dea Certe says, it appears this is true, and not only that but the airlines spy on their employees to ensure compliance with this and other rules. This, I believe, is at the root of what I was saying in my fourth point. Americans appear to live in fear of their jobs much more than do their European counterparts. It starts with company interference in your personal life before you are taken on, and continues to the frequency and ease with which US employees are fired by their companies. I can fully understand why this would engender more the 'jobsworth' attitude, especially if they already know that they are being spied upon.