This is a followup to Is there any specific reason why Delta Air Lines doesn't have its own callsign? I was... "helpfully" informed that, um, actually, Delta Airlines does have its own callsign, it's "Delta".
So, let me try this again.
Having an airline callsign be the same as a letter code word in the NATO alphabet creates a huge potential for misunderstanding. Indeed, the controllers at Atlanta, Delta's headquarters, use "Dixie" for the letter "D", specifically to avoid ambiguity with the name of the airline. It seems to me that it would be much simpler to just assign the airline a different callsign. Is there any specific reason why this hasn't been done?