Okay maybe I think too much about worldbuilding (I know I think too much about worldbuilding, this is my life), but since liraelgoldhand mentioned it I just really dislike the idea of taking an earth-culture/usamerican/christian/etc holiday and transplanting it wholesale into a fantasy world, with perhaps only a fresh coat of paint and a new name. Like— a solstice festival where presents are given/a pine tree is decorated/etc, or a festival of love where people give chocolates to their significant other.
It just smacks of laziness and lack of thought about the history of a culture and its customs. Every custom is rooted in a deep history and sense of cultural identity whether or not the people participating in the custom understand it. It’s a great way to add depth and a sense of history and longevity to a made up fantasy society— it gives the sense that there were people who came before Our Heroes, that there will be people who come after, that what we are seeing is only a tiny slice of the vast pie of the history of this world.
And I don’t really get why you wouldn’t want that in your writing?
Then again I think too much about worldbuilding.
One of the other things that really irks me is that, when people transplant USAmerican/Christian/etc holidays, it seems as if they are acting under the assumption that USAmerican/Christian holidays are universal? Which they’re really not. There are plenty of people who DON’T celebrate Christmas/Valentine’s Day/Halloween/(insert appropriate holiday here), whose cultural landscape does not include these celebrations— so why do fantasy worlds (which in many respects differ greatly from any earth culture) have to feature these holidays?