Heres my theory: Magic: The Gathering is a collectible card game and Fat Packs are more collectible than regular boxes because of the inclusion of dice, set guides, card boxes and (at one point) novels
Once each player has used the Pass action consecutively, the Action Phase ends and the Regroup Phase begins, which just involves drawing two cards, choosing to play a card from your hand as a resource and readying all of your exhausted cards (moving them from being sideways to vertical)
As Hecteyes's ability resolves, the next opponent in turn order (or, if it's an opponent's turn, that opponent) chooses a card in hand without revealing it, then each other opponent in turn order does the same
It's a self-contained box of nonsense to draft with your friends, rather than a draftable set that might also give you a valuable land, or let you build a new Commander deck, or break Legacy
Themes like creature sacrifice, recursion, and lifegain/life drain are very frequent WB themes in EDH
People will scoop up this product left and right, which bodes very well for retailers and brick-and-mortar stores selling the product