why accepting the business dining rules is important

What rules are you referring to?  Don't slurp your soup, elbows off
the table?  Some sort of monetary cap?  Is this for a particular
culture/jurisdiction?  If you want a researcher to help, you will have
to be clearer.  (You may also want to pay more.)

Holy moly! There are too frickin' many "rules" these days. It is my
firm opinion that one should not accept "the business dining rules"
without first knowing what the heck they are, and why. A little
rebellion might be just the thing here. Let's give the business to the
rulemakers and dine however and wherever we please.

Business dining rules are just a form of etiquette:  rules governing
socially acceptable behavior.  If you ignore them, it distracts from
the subject of the business being discussed, draws unwanted attention
to yourself, perhaps makes you appear to be the wrong person at the
table to be representing your company.

Seriously, I cannot see why there should be any difference between
"business dining rules" and common table manners. I'm hoping the
customer will enlighten me.