Murray-- I see your point with respect to melodies, an aspect of the topic not raised until you brought it up. I agree that the nuances of traditional melodies are quite important, and should not be sacrificed in the interest of catering to mass market, or from just plain laziness.
I don't agree, though, that any of the word changes except mishearing perpetuated by laziness deserve to be called disrespect. Hey, old buddy, I wouldn't invest so much time & money into music, instruments, research, etc. if I didn't have absolute respect for the art form. To go back to my two favorite examples--"traded" and "airbrakes"--I made those changes, etc. in the interest of making the songs more attractive to the audience, so am I "dis-ing" the originals?? I think not. If I perform "Ring, Ring de Banjo" on a fretted instrument with steel strings and a resonator, am I trashing the music or allowing it to be heard and appreciated easier?? Finally, one could parody a tune to make fun of the tune, or parody it to apply it to a modern situation, a la "urban folk." One man's "disrespect" might just be another's "adaptation."
I hope this comes across as a discussion, not an argument.