Random thoughts:

#1: Some folks are dead. Still their music is very much alive.


#2: If Folk is dead we are playing dead music. And we play it "live". Can music being played live be dead at the same time? Sounds absurd to me.

#3: Therefore the statement "folk is dead" can only mean the writer doesn`t consider it relevant for him or his peer group or the music industry. Irrelevant for the industry means that there is no big market, but maybe just a small niche for a kind of cottage industry. From that point you could just as well state that organic food is dead. And fast food is relevant.
Irrelevant for himself or his peer group? Lots of things are irrelevant to me and my peer group. Techno or rap music or soccer. Logically they all must be dead too.

#4: Statements like "folk is dead" themselves are deadLY BORING.