I read thru the whole...loooong....article and came to much the same conclusion...a slick pop article about what is essentially a pop scene. (I doubt very much if Ani deFranco routinely refers to herself as a folksinger.)
I know I'm way out of the mainstream these days, but I have known a lot of nonprofessional folksingers over the years and have never seen any particular sexual persuasion among them...they've come in allsorts, just like the rest of the population.