I hated the destruction too. But I felt that Susan had been declared to have forgotten, because she was the one the author felt didn't really matter -- can't sacrifice Lucy or Jill, because they are main viewpoints; Eustace and Edmund were 'saved'. That left Peter and Susan, and Peter was a *boy*. But I'd have believed it more of him -- there are so many more ways in which boys get to be important in the real world.