It's just Bean's character. I think Ender did just fine. Smart as he is, Bean doesn't see the whole picture.
Not that there aren't things I'd like to change about Ender's Game, but mostly those are technical things that reflect my changing tastes. A few changes, though, arise from the fact that in writing the movie script for Ender's Game I came up with some cool stuff that I wish I could put into the novel! But that would be cheating. So the movie will have some fun surprises even for diehard aficionados of the book.
If you thought Bean disapproved of Ender, wait till you read Petra's book ... and wait till you see what Bean thinks of Peter!