Ditto to everything Willng said, especially this part:
You're looking at the twelve elements as if they're all identical when in fact each one is supposed to have its own niche and advantages which the others do not possess
In the case of life, that is more efficient creatures for their cost, which in the years to come, as we get a larger card base, should become more apparent.
edit: Although, I'm not sure I agree with the part about firefly being bad; I've used the unupped one before in hope decks and things like that, even in otherwise upgraded decks.