People dont always walk their talk. Good that he resigned.
Well... I think he could have opposed the public manifestation of this stuff while still carrying it on, and not opposing others carrying it on, in private. By definition that isn’t hypocrisy. It’s probably the best tack that the “secular world” can take. It needs evangelists in order to go further.
The bigger issue was that it was in his office, that is supposed to be a public facility. If you think it doesn’t belong in public, fine! But then practice that too, realizing the status of where you are.