I can't speak for everyone, but for me and the people I know, it is ultimately the tournament community (Europe got the bestest people <3) that have people coming back, even when they have stopped reading the fictions (or even stopped playing the CCG too! Just look at the amazing turnout for Worlds in Sheffield last year).
At some point all of us obsessed over the story, and at some point some fell of away from that. There was a huge drop in story-followers before Emperor. A short visit in on the story forum was a testament to that when fiction-discussion averaged around 2-3 pages, compared to the 10+ we used to have before that.
The people you meet at the tournaments is what seemed to keep people around, imho.