I think Jerry has it right about laziness. Yes McG, we hear songs, even Beatles songs, sung with the wrong words and it really grates! And not just Lennon & McCartney ----there's a whole generation who, thanks to Mick Hucknall, think the line in 'Ev'ry Time We Say Goodbye' is 'I can hear a lark somewhere WAITING to sing about it'. If I hear anyone sing that I slap them about the head and ask them exactly what a lark sounds like while it's waiting to sing? (Clearing its throat? Practicing its scales?) Then I tell them to go away and listen to Ella sing it.Sometimes the message gets through, but I worry that it will eventually become common currency, even though it's patently wrong.
However, the point, when I started the thread, was that some people seem to feel that they have the right to decide that certain lyrics need to be changed, and they're just the person to change 'em by God! (Changing the chords is part of the interpretation and arrangement, but surely for any songwriter the lyrics are the meat of the thing.)If they feel that they have something to say on that particular subject why don't they go off and write their own song? The poor schmuck who wrote it was probably reasonably happy about what he'd written. I don't and I'm sure Harvey, Jerry, McGrath and others above don't put out a song until they're satisfied that it's finished; that it says what they want to say in the best way possible. I could name a dozen popular songs that have lines that make me cringe, that sound sloppily written, and could be revised very easily. But I don't want to sing them. When I hear a song that moves me enough to want to cover it I go to as much trouble as possible to make sure that I have the lyrics exactly right, and the melody as close as I can get given the limitations of my voice and guitar technique, but I pay the writer of the song due respect by singing it as he or she wrote it.

BJ