Discarding Unusable Activators...

[gameplan.exe]

So, is the opposite of printing "Affected cards are not discarded" on the card - not printing "Affected cards are discarded"?

right, because that's the norm. writing "affected cards are not discarded" is making the exception. Otherwise, cards that cannot be played are, by definition, unusable...

btw, I dislike that "discarding" is equal to "playing" since there's a separation in a card like a JA, which specifies that the discarded PC must be playable by the holder of the JA. If "playing" and "discarding" was the same, then the card wording would be redundant (not that there aren't other redundancies  ). So, I think the ruling was faulty in it's judgment, but them's the breaks.