Other holidays do not have as many tunes associated with it. Easter is not known for its string of songs. There aren't countless songs about Independence Day. Even St. Valentine's Day, which I would assume might inspire a library full of ballads, does not have that many specific songs to commemorate the annual occasion. Halloween has some, but not many. But Christmas has spawned so many songs that radio stations can play song after song without having to resort to repeating any tunes (unless it's something that the DJ loves.)
Some Christmas songs are classics that I do not mind hearing any time of year. Others are fun to hear once or twice. Still others are slightly annoying, and others are unbearable, yet I end up being tortured by their sound piercing my ears every season.
I will not name them for fear of insulting any of you that might like them or hate them, for my tastes are obviously not your own. But feel free to let me know your thoughts and then I will be happy to share mine. Merry Christmas!