Meh - You guys are not thinking multi-dimesionally. Why is everyone looking at luciferin and white nymph for combos with only the existing cards?
More cards will come in the future...
That is why white nymph has an active skill: what if a new card also gives a skill to skill-less creatures? If luciferin would be passive the two effects would be in conflict and one of them ignored all the times; if you have to click to activate the skill, you get to choose.
Also, there is no need to click on white nymph endlessly, just once, when you play a new skill-less creature.
Finally luciferin opens a road to new game mechanics, example:
I am planning on adding the "Fractal" card to aether: Select a creature (on the field). Fill your hand with as many copies as possible of the creature's card.
You get up to 8 copies of that card in your hand, no modifications are copied and you have to pay the card's cost if you want to use it. If you pick a cost-less creature you can get up to 8 creatures out in one turn. Add the luciferin effect, and you played 8 light pillars in one turn.
Last thing: why compare archangel (upgraded) 7/7 with white nymph? Unupgraded? The upgraded version will probably get better stats.