I'm surprised that this issue hasn't been addressed yet. The current behaviour of Purge is pretty unintuitive; but from my point of view the big problem is that it doesn't do what the card says it should do. . Based on that description, it should discard enemy-owned handicaps, such as Festering Guts and Blind Rage - but it doesn't.
Additionally, it DOES discard 'enemy' handicaps granted by the players from radiation, and only those. Since they count as allied cards.
Related: Shrug It Off apparently will discard handicaps you've played on yourself, even though the text says "enemy controlled cards." Misleading!
So... It's just an as-intended thing that random enemy attachments can definitively cause losses without being able to purge these effects ever? I know you can't have a counter to everything in a single deck, but leaving a gamechanging mechanic that is only counterable by one race (dwarves - shrug off) seems a little strange.
i just saw, if i am not mistaken, a human wizard use lateral thinking to successfuly free himself of an handicap i gave him by radiation goo. I think thats worth noting in this context.