It is no worse financially than those Grand Boasting Sessions that used to waste your money every summer. Travel, hotels, donations--all waste more money than worshiping the sun. And, you can cut back on things if things are really so tight that you simply can't afford it--one should never go into debt just for a holiday that recurs every year.
But, if you compare the expense of Christmas with the jokehovian expenses, Christmas celebration is actually cheaper. How much did it cost per year for car expenses for field circus, for instance? How many gallons or liters of gas per week did that waste? And wear and tear on the car? Suit dry cleanings, eating big macs every single day, donations, and whatnot also add up. Unlike worshiping the sun, you cannot cut back on field circus expenses without the hounders saying something about it.