I am not a member of an organized religion but cannot say that I am totally not religious. But rather feel that there may be a grain of truth to most of them and try to keep an open mind about them. I was raised in a Christian household.
I celebrate Christmas mostly for sentimental reasons. Remembering my youth when it was one of the happiest times of the year. The smell of the Christmas tree, the lights and decorations, the music, the toys, the children's joy, the snow (sometimes), the turkey dinner with family gathered around, the good will. These things make me feel happy and content and we try to repeat/relive them every year.
The fact that your store and others seem to be starting the holiday earlier and earlier bothers me mostly because I'm afraid of getting too much of it too soon and getting burnt out before the end of the year.