For anyone not visiting the linked thread, here's one of my posts to it:
I'll try to put this delicately...
Since we're now in the "Safety Corner", my concern goes beyond someone using a groundspeed display as a landing aid, or to use GPS groundspeed to avoid stalling. Many experienced pilots and instructors here have already deemed these actions unsafe, and they are - for easily seen reasons.
The flight instructors here have all been taught to look for certain "Hazardous Attitudes" in our students, other pilots and even ourselves.
They are: Macho, Anti-Authority, Invulnerability, Impulsivity, and Resignation.
ussyorktown's response to the advice here falls, I think, into the "Anti-Authority" attitude. The snarky and sarcastic comebacks are not indicative of an open mind that really wants to learn. Similarly, his reluctance to engage at least one instructor here (me) by responding to his questions seems to me to not be conducive to learning. And pilots should always be learning, whether they have 50 or 5,000 hours.
I took the time to engage and put forth questions and thought experiments that might have led ussyorktown to that "Aha!" moment that instructor's yearn to provoke in their students. If that effort is for naught, well, so be it. All I can do is try.