Singing a song and reading, or reciting verse are different things. Sometimes adjusting the words as written seems perfectly right to me. Often a song will involve shortening a text, or adjusting the phrasing, or changing it in other ways.

There's no disrespect to the author implied.

It's not that different from the way that in a production of a greatly admired text, say Hamlet, the play is shortened or the words amended. Shakespeare isn't turning in his grave. The performance is what matters.

Sydney Carter had the right of it in my view, when he said that he wanted people singing his songs to feel free to change them as they wished, and that he saw that as a way of keeping the words alive.