I used to work at Manchester Airport. While some of the staff in security are a bit ‘mardy’, they are by far some of the more friendly I have come across throughout the world.
Even as a passenger before I worked @man, the staff seemed efficient and even helped elderly passengers or families travelling with young kids. They are employed directly by MAG so if you feel so abused then maybe write to Andrew Harrison, MD.
Or maybe it was your demeanour when passing through central search? Only having had Silver DC and flybe R4A, I cant admit to having the swagger of a Gold/Platinum FF, even if I have abused a card in the family that has the same initials on it.