I never heard of that rule.
Other than the majority of citizens (I swear I heard or read this somewhere but can't prove it) are atheistic in nature. Israel is supposedly a Semi-Theocracy, or something.
There are certainly a lot of contradictions over there, but tour guides or directors ought to be a little more intelligent than to be steering folks into places where they know others are not welcome.
I make a lot of assumptions here.
"Oh honey, look at the old fashioned Orthodox Jews. lets go tell them about what things are really like."
I can picture stuff like that happening.
It is an unspoken rule but it is vigorously enforced as any ethical person can see from many of the posts on this thread including yours.