It is an incontrovertible fact that you can be impeccably punctilious about all the trappings of manners - opening doors, pulling out chairs, walking on the roadside edge of pavements etc. - but still be appallingly rude. The call centre employee has been well-coached in the etiquette of the cold call or the politest way of handling complaints - yet, with every meaninglessly courteous and obfuscating syllable that falls from their lips, we are driven to incontinent rage. Politeness is not a failsafe measure of manners.
Manners are valuable in this world for the simple reason that well-mannered people know how to set others around at their ease, know how to make the world feel a more civilised, friendly and calm place, and like to put others' comfort ahead of their own.
If politeness demands that dinner parties are seated boy-girl, boy-girl, good manners demands that when your guests take it into their heads to sit randomly, you just smilingly go with the flow. If being polite and opening a door for someone means that you have to wrestle your way past them in the first place, almost knocking them flying, then why not stand back, relax and with good manners acknowledge their own kindness in holding the door open for you.
Yet don't cast politeness out entirely - it is a good plank in the raft of manners and should be respected as part of the social contract we should all tacitly enter into to make our world more harmonious. In a society where behaviour is becoming increasingly loud and brash, we need to preserve politeness as the vital ingredient in the cocktail of manners that makes our world a better place; somewhere where basic survival is finessed into a more subtle pleasure. So bring back the doffing of hats, bring back the polite boardroom, let's have unisex chivalry.