If there are bad apples in a team, they deserve some kind of presumption of innocence. The manager should at least try to find out what's wrong. I've seen bad apples who were frustrated because they weren't listened to, and they did have good ideas which they could explain. In those particular cases I did not witness how this situation developed, but I have no doubt that bad management can produce bad apples.

All you can say about bad apples is that they point to a problem. To fire them without asking is shooting the messenger.