I fear my original post has rather lost its way in the comments abut engineers and doctors!
That would be my fault. Sorry, valid point!
To connect the dots (well, the ones in my mind, anyway) the insignia is just the public presentation of what the wearer has achieved in a publicly recognized discipline. To dishonour the insignia is to dishonour those who have earned it. Be the insignia pilot wings, an iron ring, or a caduceus, it is the [legitimate] wearer's privilege to be seen displaying it. Our society shows our respect for a person who has achieved recognition in a discipline by respecting the insignia associated with that discipline.
Pilot wings, perhaps more than other insignias, come in many variations. If a pilot wears generic wings, I'm confident no one has issue with that - they're a pilot. However, if the specific wings can be identified as the insignia of a distinct pilot discipline, we owe it to those pilots to show them our respect by rejecting the misappropriation of their earned insignia.