Yep, I´m always saddened when I come to the departure gates for my flight back to Europe - during your stay you saw almost everywhere smiling and friendly people, and while you´re waiting to enter the plane, you can easily identify (from the faces, not only from the sox to the sandals) who´s German/European and who´s an American passenger. Really sad!
Ahhhh come on... complaining on that only makes you one more depressed german.
I work for people in swabia and they definetly invented grumbling. But I think they just perform best if they are in a bad mood. If they really hate something they are about to change it to the better.
That's not true for me but my mood is not affected by swabian grumpies - maybe nexttime in an airplane do it like I do - just sit next to a brasilian girl and focus on the world cup.
The you will easily make an example for an throughout optimistic german.