Simply loved this thread! Meant to dip my finger in earlier but was too taken with the direction the thread was taking. The HD fellow essentially gave the most palatable and universally acceptable response, with another response correctly explaining it to be non-standard.
If there was to be a “history” to this practise it may very well relate to the days without radar when ATC’s were applying separation and procedures born directly from the information supplied to them by pilots. This absolute reliance on ATC guidance during procedural/non-radar control possibly elevated ATC’s to a level that deemed the use of the word “Sir” as par-for-the-course. This is however just my conjecture.
I have some ATC colleagues who use the word “Sir” with a frequency that matches the bowel movements of someone with dysentery and is equally as unprofessional as it cheapens what I would imagine to be nothing more than a mutual respect for each others careers.
To me, “Sir” or “Ma’am” is of no consequence, what matters are quick finger-on-the-button responses.
TDR