I seriously doubt that the reason it hasn't happened on a US server is because people run from a fight... at least not my server, and not in Tier 4. Sure, there are always a few people who get to T4 thinking that BO surfing and RVE is the best way to earn renown, but they are by no means the majority.

I'd be curious about the population balance on those European servers. My US server is very well balanced, which means that a push by either side is usually met by strong and fairly well-organized resistance.