According to therapists, counselors, social workers, and psychologists, the winter holiday season really isn't the "most wonderful time of the year" for many people. Normally, Christmas is supposed to be about celebrating with family and loved ones, and I think that's a noble aspiration. But as other members have mentioned, not everyone has a reason for the season.
Add to that the anxiety and social pressure of buying "the latest and coolest" presents as a way to fit in, not to mention the crushing post-holiday credit debt that inevitably follows (and knowing that your gift was rudely returned for credit towards something the recipient actually wanted), and yeah the holidays don't help much. Plus, everyone's saying you should be jolly, you should be happy, but that the holiday isn't really yours because you're not of their religion... that's one heck of an abusive mindset, when you think about it. Especially when you see large parties and dinners, attended by lots of people raising a pint and singing off-key... and everyone you know and/or loved is either dead or wants you dead.
People make a lot of money by subconsciously hurting you back into Stockholm Syndrome every October. Even Krampus would get a bit Kranky about those types of shenanigans and tomfoolery, with Jacob Marley tagging along as his sidekick.
Growing up, my holidays were nerve-wracking and involved at least one adoptive parent going at the other. There are one or two holidays that I do have good memories, one was when I first visited my grandparents at their Minnesota farmhouse in 1985. The other was in 2004, when I was recovering in Gainesville and realized that I had no family left. I think that was when I realized why Christmas was so horrible for so many people, despite the joy it kept promising.
Christmas isn't a holiday. It's not a blowout sale, it's not a shiny new gadget that breaks before Valentine's Day, it's not the festive dinners and depressing (and creepy!) decorations. It's not a thing, it's not even an event. It's a celebration of death and rebirth (the deity in question doesn't really matter, the names change but the song's always the same), a time of letting bygones be bygones and starting the new year with a fresh, clean slate. Another chance to live, love, laugh, forgive, forget, and just be in the unbearable lightness of being.
It's a chance you don't just celebrate once a year. If you're really lucky, you learn to celebrate it every moment of your life.
"People were created to be loved. Things were created to be used. The reason why the world is in chaos, is because things are being loved and people are being used." -- John Green (but said by many others before him)
Maybe Jacob Marley had it right, after all. Christmas ain't about giving presents to others. It's about celebrating the life we were given, for better or worse. Comparing what we've got against what someone else gets... that's why the holidays affect people the way they do. That's why people become so miserable, because they feel forced to be something they're not. To do something they know they can't afford, for something they'll never gain.
Don't compare what you have against what you don't have yet. Let your own bygones be bygones, and at midnight, January 1st... face the new year with a clean slate. Choices, gotta love em.