Granted, our major source is those Rebel propaganda epics, but it seems like a strange detail to include- so I think that line may in fact be an effort to introduce a slight element of verisimilitude.

Counter arguments can be made for Skywalker's campaigns upon Geonosis. However, the general historical record of Lord Vader shows that he did not ever have a particularly good time on any desert planets, frequently suffering physical trauma and personal losses during his visits there.