https://americanreformer.org/2024/11/the-death-of-thanksgiving/
Dunson is upset because of the commercialisation of Christmas and the fact that the 'season' starts in conjunction with Halloween. Thanksgiving is skipped over.
The answer to this is obvious. We live in a capitalist society and with a retail economy, Christmas is critical. Thanksgiving is only a boon for the grocery industry. The Utilitarian ethics of capitalism make it so and make it right. If he has a problem with this, critique the system and the values its spawns - but don't hold your breath. He is writing after all for the American Reformer.