For our family, there is a bit of history.
My grandfather owned a small town meat market. During the holiday season, the Mexican men in town wanted a good cut of meat for the holidays, but didn't always have the cash. He would take homemade tamales as part of a trade. With that, our family got to eating tamales during Christmas, specifically on Christmas eve, and the tradition was born, out of some generosity by my grandfather, and a willingness to make good with another man on the other side of his butchers block.