I've often heard the souls in Purgatory referred to as the "Poor Souls," the "Unfortunate Souls," and the like. This has never made sense to me; why call them this? While it is true that they are undergoing a harsh purification, the souls in Purgatory know for a fact that they will eventually be in Heaven. What is poor or unfortunate about that? The certain knowledge of the Beatific Vision would seem to make even the most severe penance bearable.
If anything, I think the terms "poor" and "unfortunate" should be applied to the souls in Hell, who will never be in Heaven.