I think Vila's "welcome to it" and Avon's "spare part" comment were their usual humour, which, sadly, Tarrant and Dayna failed to get. Than Avon taking Vila off weapons and leaving Vila functionless really didn't help. I'm not surprised he became depressed with 1) constant putdowns from the Tarrant and Dayna and 2) nothing to do and no way to keep his mind off fearing the worst. He's fine if he was something to do.

I blame the writer (esp Boucher who was script editor) too. Nation's scripts always had more complex characters all round, and a Vila with wit and an edge.