So what you write is really the basic truth: Try to contribute to the wellbeing of people around you. That shouldn't be so hard.
Coughing is not necessarily the problem. You can cough without having a respiratory disease, and respiratory disease can transmit without coughing.
It's impolite to ask.
> I also have never coughed on an airplane
lol, sure
In some Asian countries it was already common courtesy to wear a mask if you even suspect you might have a respiratory disease before Covid. Saying everyone suspecting a respiratory disease should stay at home is fine but detached from reality, people need to go places.
Ergo, wearing a mask in closed spaces is a compromise between being grounded and being an a** h***.
Edit:
About this
> I do contribute to the wellbeing of the 95+% of the people who choose not to wear a mask and want to engage in human connection with the full range of emotional and facial expressiveness we were blessed with for that purpose
What exactly is the benefit strangers in a closed space (like public transportation) get from seeing your facial expressions? What kind of human connection do you expect with strangers on public transportation? Believing the viewing of your face to be to the benefit of the public is narcissism unlike any other.