As the boys realize here, in Jesus vs. Santa, Christmas is about presents. Not ham, not goodwill towards men. Presents.
And fantasy gaming is about treasure. Delvers aren't wasting their time in deep dark holes that don't have treasure laden monsters.
Let's take a look at some evidence, shall we?
Moldvay D&D: ". . . heroes venture out on dangerous quests in search of fame and fortune. Characters gain experience by overcoming perils and recovering treasures." (p. B3)
Holmes D&D: "The party then enters the underworld, tries to capture the maximum treasure with the minimal [sic] risk and escape alive." (p. 41)
AD&D DMG: "Wealth abounds; it is simply awaiting the hand bold and strong enough to take it! This precept is basic to fantasy adventure gaming. Can you imagine Fafhrd and the Grey Mouser without a rich prize to aim for? Conan without a pouch of rare jewels to squander?" (p. 91)
Rolemaster Creatures & Treasures: "One of the chief goals and rewards in fantasy role playing is 'treasure': money, valuables, and magic items." (p. 1)
Dicing with Dragons: An Introduction to Role-Playing Games: "In the short term, players will act co-operatively in pursuit of some common objective, such as the accumulation of wealth and power . . ." (p. 6)
Dungeon Fantasy 1: Adventurers: "But something else resonates with nearly every gamer. That's the thrill of taking a powerful, faux-medieval adventurer down into a cave . . .and seeing lots of monsters, killing them, and taking their treasure." (p. 3)
Dungeon Fantasy 8: Treasure Tables: "Reduced to its essentials, the dungeon fantasy genre consists of sword-and-sorcery heroes with cool powers killing things and taking their stuff." (p. 1)
The Dungeon Alphabet: "It is for gold that the brave or foolish venture into these unwelcoming subterranean locales." (p. 13)
Oh, sure. You have your fight against evil, and your heroic rescues, and your exploration of the deep dark. You have your reindeer and elves and lights and religious observances and being of good cheer, too. But you're shopping for and exchanging presents, and adventurers are delving for treasure.
Merry Christmas, and may all your opponents have 100% of Treasure Type H.