My wife and I quit celebrating Christmas several years ago. After the kids had grown and moved out it just didn't seem to make sense. Both of us are agnostic, my children weren't raised in the church and the holiday shopping is just a pain in the ass so we dropped the pretense and freed ourselves from the added stress and expense. Now we just shop for a few toys for my grandson and send our adult children some money.
Why go through all of that hassel just for a social custom that's becoming more commercialized and marketed every year?