These days you can't walk through a shopping mall without seeing lots of navels of display...

Still that's not what this is about I suppose. As for people knocking "navel-gazing" as a genre, accept that as a rule, and there goes all Shakespeare's sonnets, most lyric poetry, any number of great songs, in all kind of traditions.

And of course a rather larger number of songs that aren't too great.

There are good songs about personal feelings and there are bad songs. There are good story songs and there are bad story songs as well. Dismissing songs by categories like "navel-gazing" is just lazy thinking.

Probably any good song involves an act of imagination by the writer - projecting themself into a situation of some kind, telling it from a point of view. It's like any kind of imaginative writing - there's an element of acting in it, even while there's also an autobiographical aspect as well. For some reason people often seem to want to extend that aspect. But really there's no more sense in than confusing the character some actor plays with the real person. There's a link, or it wouldn't work, but there's rarely a one-to-one correspondence.