At one point, we decided to do a massive errata on dozens of cards that were printed before wording was standardized. At the time, this made sense, and Redemption did not have very complicated or diverse Special Abilities, so it was fine to just say "oh well Plague of Flies wasn't meant to have a Discard ability, it just tells you what to do with characters that reach 0 defense." Everyone accepted it at the time, but in the future we now have much more complex and diverse abilities, and "if character reaches */0 or less, Discard that character" could easily be an actual Special Ability. "Only a Rescue Attempt of two or more Heroes may be successful," while it would need to be play-as'd to "Protect Lost Souls from Rescue by a lone Hero," is also a possible real ability.
The only reason we've done away with these additional abilities on many old cards is that they weren't intended to do that at the time. Our policy today is to not errata cards because they ended up doing something unintended unless they're not functioning as printed. What benefit is there to having scores of old cards, some of which would likely be usable with their full ability, play differently than what the card reads? Unless there is some huge offender (who we could just give specific errata to since its currently errata'd anyway), as I see it the only benefit to the sweeping "clarifying language" class of errata is none benefit, at the downside of having many more cards a new player needs to obtain special knowledge about (and to be honest, in preparing for this thread I have not been able to find a list of this class of errata) to play properly.
