Covenant,
I'm sorry you were not accomodated. Many US carriers will not allow upgrades (for free) or even if the fee is paid in advance if a meal is not available. This is the company policy at my airline. Even if economy is full and it means the non-rev gets bumped, the agents cannot allow the upgrade!
Unfortunately, some US carriers have "ghost riders" on board. That's a pax flying undercover who reports on everything from check in to baggage claim. We never know when they are around and what it is they may see. Maybe a good idea from a quality control point, but it does make us a bit nervous to try to help some one out as much as we want to. Does such a thing exist on European carriers?
Since most of the flights I work F/C is usually full with upgrading frequent flyers, I don't have the opportunity to extend this courtesy to my coworkers from other airlines. It's a shame, I think.