I do know people who don't enjoy Christmas because of unhappy memories - a close relative died at that time, or parents were always bickering, etc. And I do feel sad for them, because it was always a magical time for me as a child, despite parents usually being hard up and not being able to afford much.
I do agree about over commercialisation and a load of unnecessary tat - however nobody is obliged to overdo everything. As for the 'perfect families' and the perfectly decorated houses in ads and on TV, I would imagine most of us are not fooled by them, any more than we think everybody else's kitchen is like something out of Homes and Gardens - acres of shiny, spotless, super-stylish cupboards and worktops in the latest must-have colour/material - with just a couple of sparkly wine glasses, a bottle of fizz, and an artistically arranged designer bowl of lemons and limes.
My kitchen certainly isn't! And our Christmases aren't Homes and Gardens, either. No artistic 'designer' tree - same old stuff, some of it ancient, goes on every year, and I have even been known to drape it in - shock horror! - coloured lights!