Why do people get het up about postcodes? It happens all over the place and it is nonsensical.
The purpose of postcodes is for the Royal Mail to route mail. They have no other formal purpose. Therefore, the postcode you get is based on which way your mail is routed, not where you are, nor where you are associated with.
Anyone who reads additional things into them, gets het up about them being "insulting", or uses them for another purpose, is doing it off their own back.
They no more identify where you live in "association" terms than your broadband IP address does.
Certain postcodes are considered prestigious in the property market, for example W8 or SW3. There is even a certain amount of snobbery about having a "proper" London postcode, rather than KT, CR, BR etc. It's crazy.