If it's fun for Euro and others interested to write some new stuff with some old characters, I don't see why anyone should have a problem with it. It's not like we're writing high literature here. Collaborative fiction is throwaway RPG-like writing meant for fun, and there are different aspects that each of us like about it. Euro may not want to create new characters, because that would not be fun for him. What is fun for him is playing with the backstory, the internal history, that already exists. More power to him. More power to you in whichever aspects of RPG/collaborative fiction you enjoy, too.

This forum is meant for people to write whatever kind of stories they want. We will never all agree on what is a preferable form of storytelling, because we each love it for different reasons.