If you play a land and use the emblem to discard every turn, you can run out of cards eventually, and the 7-drops in the Momir pool (for example) mostly provide better value than, say, the 1-drops. At least that used to be the case when the decks only had lands. Now the decks have some non-land cards, and if some of them help you draw (can’t remember which cards are in there), maybe it doesn’t make as much sense to pass early.
I bought Fallen Empires packs frequently when it was the current set. Seemed like a good idea at the time.