That question was really supposed to be simple, but it's nice to see a discussion started up.
My knowledge of post-modernism is related to vague remarks on Charlie Kaufmann movies, tidbits from non PM-focused university classes, general laymen chatter.
I had this question, because I am not really a fan of "noise" stuff, and think it's ridiculously pretentious and more or less an attempt for hipsters to separate themselves from a increasingly commercial indie music community, by way of something "much more smarter, intense, and mind-blowing." I personally would have been turned off by the idea of circuit-bending, had not one of my favorite bands introduced me to it. Now, I can enjoy some noisier stuff that I ever could, because the absurdity of seeing a CBO used in a live setting, and hearing computers lose their beans is entertaining. I don't see it as mind-blowing or smarter...just messier, more unpredictable, and less confined.
The complex CBO, with fancy paint job and careful design, does strike me as an art, not just a technical skill. My high school passion for electronics was only resurrected this year when I found out I could make new, totally unique instruments.