I thought the same thing at first, but after testing
Nissa's Pilgrimage (similar to
Cultivate) ended up going with
Primal Growth because the land comes into play untapped. So if I have a
Fyndhorn Elves,
Elvish Mystic, or
Llanowar elves in my hand and use one of these to play
Primal growth then I can pay the kicker and use the extra land to play another creature same turn.
Example:
starting hand - 2
forest, 3 one cost mana generating creatures,
Primal growth, and
Giant Adephage.
Turn 1 - play
forest, play
Llanowar ElvesTurn 2 - play
forest, play
Primal Growth (sacrifice
Llanowar Elves for kicker) to play 2 forests (untapped), play 2 more
Llanowar ElvesTurn 3 - play
forest (you may draw another
forest by now), play
Giant AdephageIn this scenario I'm able to play a 7 cost creature on turn 3, but wouldn't if I had
Cultivate or
Nissa's Pilgrimage instead of
Primal Growth.
Primal Growth also makes it easier to play
Panglacial Wurm from the deck than
Cultivate or
Nissa's Pilgrimage since the
forest comes into play untapped.