In Len Deighton's excellent and well-researched book Bomber there is mention of resentment among long-serving NCOs who had worked their way up through the ranks seeing the Sergeants' Mess suddenly filled with 19 year old boys with brand new stripes on their arms. Did you experience any of this?
You don't have to read a book or go back too many years to answer this one. just ask any of us "plastics". OK, it was not an every day occurrence, neither was it a rarity and sometimes it was a little full on.
FWIW I went to Sleaford Tech as 32 year old NCA Flight Sergeant and I was a called a plastic to my face by a course "mate" who was an SAC Admin Sec. He flunked IOT and got recoursed and then totally failed Navigator training as well.
Chiselling little dritzekt.