Why are all "great" songwriters white guys with acoustic guitars?

I try not to do too many 101-posts here. A few years ago, I wrote for a site where the bulk of my posts were 101-level, usually along the lines of "here's another thing where women are grossly underrepresented. Let's discuss why." Those posts are important, but it gets tiresome after awhile when you expect women to be underrepresented, and let's face it, when asked to name "great songwriters" most rock fans will go through a progression of (mostly dead) white guys before they name a Joni Mitchell or a Laura Nyro.

Throughout the past decade or so, I've been a member of a handful of music fan forums. I'm not a member of No Depression (though I did at one time read their print magazine), but this is pretty typical of most fanboards' High Fidelity-like nature: Who are your five favorite songwriters. Ooh wait. I think I know the answer to this one:

dylanneilyoungtowneshanklennonmaccatheboss...

Never really varies much. A few ladies were named: Lucinda Williams, Laura Nyro, Patti Griffin, and Joni Mitchell came up more than once. Some women were completely written out of history, in particular Kathleen Brennen, Tom Wait's songwriting and romantic partner, who is never mentioned while Waits himself gets full credit. Save for one vote for Bob Marley and a handful for Robbie Robertson (Native American), POC are entirely absent.

I'm not trying to single No Depression out; they're no different from any other blog or forum I've been on. Not so curiously, when I've pointed this out, those same fans are able to remember tons of female and non-white artists. But unless prompted, they revert to the familiar. One promising thing is that maybe the High Fidelity school of music criticism is dying out (or aging out). Paste magazine, when it was still a print publication, asked its readers to name their favorite songwriters in connection with its critics' favorites. The readers' lists was a lot more diverse.