At Thanksgiving, I say Happy Thanksgiving. At Christmas, I say Merry Christmas. On New Years, I say Happy New Year. Isn't that what you do?
Sure but if I just see someone in passing that I doubt I will see again during the holidays, I tend to wish "happy holidays" instead of making a list. To people working in the stores who are busy all season, I do the same.
That said, when I leave work for Christmas vacation, I will wish my co-workers, etc. a Merry Chrismas. Same with family and friends that I see fairly often.
Don't get me wrong, I see your point. If you Google "Christmas Sale" you are going to be very disappointed. Evidently, no major retailers use that anymore.