Diane,

your quote is about business. "Folk" has been so "out" for the musical industry`s customers that is weird enough to... well, name a newly fabricated trend.

The musical industry`s definition of folk: anything with an acoustic guitar.

Back to the original topic: I think a song is political if it is/was intended to be political by the writer/singer. So the songs labelled with the f-word ;0) can be poltical or not. Business hasn`t that much to do with it: even a political song has a commercial aspect if the writer/singer makes a living (even if part-time) with his music. The market for political songs is smaller than the market in general, but nevertheless...

Best
Ernest