Obviously it's a shame to lose a player of that ability, but I would say that we don't know the full story. All we see is the results on the pitch, if he's making life difficult for the rest of the team behind the scenes, then it shouldn't matter if it's Kevin Pietersen or some no hoper who is a one cap wonder. He's caused problems wherever he's been, so it's not like it would be out of character for him.
Sure, I'd much rather see him play, but the England team is bigger than just Kevin Pietersen.
I just hope some of the talented guys from County Cricket get a go at replacing him, rather than just the same old names.