Why does Holden believe Christmas plays are unreligious?

From the text:

Then, after him, they had this Christmas thing they have at Radio City every year. All these angels start coming out of the boxes and everywhere, guys carrying crucifixes and stuff all over the place, and the whole bunch of them--thousands of them--singing "Come All Ye Faithful!" like mad. Big deal. It's supposed to be religious as hell, I know, and very pretty and all, but I can't see anything religious or pretty, for God's sake, about a bunch of actors carrying crucifixes all over the stage.

I said old Jesus probably would've puked if He could see it--all those fancy costumes and all.