Nicely put, Daily - I agree 100%
The point surely is that standardization is the most important lesson here.
Yes; some folk - flight deck or ATC - may think they are very clever and professional just because they sound cool and slick with their invented calls and linguistic shortcuts, but if they are using non-standard phrases that even just one crew does not understand one day, and that crew then taxis into an aircraft taking off, or descends into the flightpath of another aircraft and crashes - how are they going to feel?
Would they be able to sleep at night?
Some ICAO phrases do seem laborious, and I do understand why some folk feel the need to make things slicker, but they must understand that non-standard phraseology could lead to disaster one day. As I've said; we were given totally the wrong QNH going into Mexico, purely because the controller was trying to save time by making his own invented verbal shortcut. Fine for him, but what if we had stuffed the aircraft into the ground in IMC conditions because we had the wrong QNH set?