I found the following text on Bob Bossin's home page http://www.island.net/~oldfolk/obituary.htm
Its an excerpt from an interview he did with the Canadian Folk Music Bulletin in 1995.
For those who don't follow Canadian folk music, Bossin was a co-founder, with Marie-Lynn Hammond and others, of Stringband, a justly-celebrated part of Canadian musical life from 1971 to 1986 (btw, he's not dead, as far as I know, despite the "obituary" in the URL).
I should also add that Bossin doesn't think that there are many modern folksingers by the following definition (I disagree).
"Folk music is the music that rises naturally from a community. As a definition, that may not be airtight, but I see it like this: Making music is an absolutely natural thing to do, as natural as running, as natural as speaking. I can sure see that in my two-year-old. People just sing. And left to our own devices, we'd sing about anything we'd talk about. People have always sung their protests, just as they have sung their love. They made up songs about their friends. About tragedies, controversies, work. They made up songs for weddings, played tunes for the dance, made up a ditty and dedicated it to someone for a birthday. If people in the community were talking about something -- cutting down a forest, putting in a highway -- they sang about it too.
But that natural music-making dropped off as the music industry took over and inserted itself between the makers of music and the consumers of music. Songs became commodities you purchase pre-fab. In order to have music, we think we have to pay Sony. We think real music is something you buy a ticket to hear. They hooked us, made music slick and mass-produced, and replaced the music that comes naturally. But the natural thing is to be singing in our own way about our own subjects, including lots of subjects that now get weeded out by the censorship of the marketplace.
That's what folksingers do; they still sing those other songs. That's what Seeger has done, and that's what I do. We're throwbacks. We are professional folksingers, which is almost a contradiction in terms, though not quite. Because while we do sing for money, we don't create the stuff for the money. If I wasn't being paid I would still write and sing pretty much the same songs. I don't think "Oh, here's a song that could really get popular" or "Here's a song that I could sell to so-and-so." I know there are people that write that way. In fact, they write some really nifty stuff. But I'm not one of them. I write about the things on my mind, which are the things on the minds of people in my community."