Easy to get all "LOL, everyone likes Christmas" and that, but it's probably not all Only Fools and pigs in blankets, innit.
I've worked with a couple of people who fucking hated Christmas. One guy split up with his bird and she didn't let him see his kids, so he used to work right through Christmas and New Year just to keep busy.
I imagine it might be pretty awful if a loved one had passed away on or around Christmas. That'd sorta ruin it every year for me, to be honest.
Something about old people 'n shit.
Maybe you just hate your family, idk.