Looking over my larp list from the last post, one thing that stands out is that half of them are light and comedic, suitable for pre-teen kids. I think there's a tendency in culture as a whole to view tragedy as more deep and interesting than comedy - particularly if the topics are highly charged and extreme. This is reflected in some of the Nordic larp scene - including American and other attendees.
A discussion I had with Wyrd Con was over the issue of bringing in negative trauma into games - like cold-blooded murder, rape, torture, suicide, oppression, etc. I'm thinking in particular of Kapo, The School Trip, the jeepform Drunk, System Danmarc, The Tribunal, and others. I don't think that these elements should be strictly excluded from games, but I do feel like they consume too much attention and analysis - when there is more interesting stuff going on in other games.
Games being fun doesn't make them any less creative, meaningful, deep, and/or educational. Fun is engaging, and draws players in to participate more, open up more, and create more. Conversely, a game isn't more deep and interesting just for having picked trauma as a subject.
To get more concrete... American larpers as represented at Wyrd Con tend to prefer fantasy or science fiction genres and more mechanics in their games than the Knutepunkt crowd. I love the Knutepunkt scene and always have fun playing there, and I'll want to draw on stuff I've learned from them when I run something at next year's Wyrd Con. Still, my Wyrd Con game will be fun in the fantasy/sci-fi and with mechanics, just also pulling in other ideas I've learned from the Nordic scene.