[Mesorah] Couples holding hands

[D&E-H Bannett]

In Areivim there has been a long discussion about married 
couples holding hands in public.

 Without mentioning the words "in public", R'  Moshe Shulman
wrote: << We are taught not to do anything with our wives 
that we
could not do when she is niddah.>>

This led to my comment: <<Please read that quote again.
Did he miss something? Did I? Did everyone?

Wouldn't following R' Shulman's teaching have a somewhat
negative effect on the percentage of Jews in the earth's
population?

To this R' Micha replied: <<There is an implied "in 
public".>>


And why is this nonsense of interest to Mesorah?

We learn that there is a "karei v'lo ketivei" in the Areivim 
mesorah just as the mesorah of the Tanakh.