The price problem isn't necessarily supply, it could very well be demand.
If players didn't really want or need the bless deeds, then it really doesn't matter how many there are in the world. The lack of demand would cause prices to fall.
You made a bad assumption. People posted bless deeds were the best thing to spend points on, NOT that they would want to buy them from other players.
The object of the event was to remove items from the world, not transform your junk into valuable items to resell. You made that assumption, not the developers.
So the developers accomplished exactly what they wanted to do.