Its hard to blame him, Xenophon effectively lost Athenian citizenship fighting for the Spartans. He owed his landed wealth and slave-holdings directly to the Agesilaus. Leuctra was nothing less than a world changing catastrophe for him; he pretty much lost everything under Theben hegemony. I know we expect objectivity from our historians, but given how personally connected he was with the Spartans, its understandable.A good example of Xenophon's bias is that in HELLENICA, he only mentions Epaminondas parenthetically, and not at all in the context of Leuctra.
Love Xenophon, but that really annoyed me.