LoN loot cards are...well...loot. Loot comes from monsters, and killing said monsters. LoN drops are about as common as master 1 chests from random mobs. I have definately gotten more masters while soloing than LoN cards! Even after the introduction of LoN. Something this rare should NOT come from crafting.
Right now we get a chance of getting a harvested rare from crafting. It is no where near as common as harvesting it was, or is. It was always more rare than harvesting it. That was put in to liven things up while crafting more than as a method of obtaining rare harvests.
We're crafters. Lets concentrate on crafting items, not getting some bonus random thing like we're adventurers hoping for rare drops.