It might have more to do with how Bean was perhaps one of the more interesting characters, at least in terms of how he was originally presented in Ender's Game and Ender's Shadow. And while Ender was interesting to begin with, over the course of these books in particular, he's become less and less appealing a character to me given how lofty a lot of the subject matter has become. Or at least has tried to become.
To be fair, this story arc has included some pretty interesting themes and concepts. We've had to deal with the question of sentience, the value of one species over another and even a little religious argumentation to boot. But then it has meandered around a lot as well and I suppose that's really begun to eat away at my personal interest in this story. But still, I already started the series and I remain determined to finish it no matter what.