I agree with a lot of what you say, with the caveat that I suspect that one or two of the 'pax who knew how to behave' in the BA lounge were Geordies as well.
Must admit, when on my last trip through Amsterdam I spied and heard (from some distance away) a bunch of people who completely refused to integrate themselves into the Business-Class Eurosoup that inhabits large parts of LHR, AMS and CDG, I experienced a strange frisson of pride when I realised that they were Geordies. But that's possibly a discussion for the sociology forum if there is one.
I agree though: Sharing a departure lounge with people who find it an essential part of their cultural identity to get poo-faced at 5.30am can be a pain.