Well, it is easy to see where he would get those ideas.
Christmas and Easter are both celebrated during the same time as pagan celebrations, whom the Christians were trying to convert.
Jews celebrate the Sabbath from Friday to Saturday, and I doubt Jesus celebrated on a different day.
And prayers to Saints and Mary could be seen as idolatry.
Add to those that the “mother of god” concept was decided in the city that had the temple to Diana “queen of heave” and Christians were having problems with merchants who sold the trinkets used to worship her. All coincidences of course.