1. The author is reading too much into too little data. Why should I believe that people saying "No problem" is "a culturally significant obliteration of the difference between giving and demanding" and not just a verbal shift? 2. "No problem" doesn't imply that the audience's thanks ought to have been an apology. Rather it's a humble reduction of one's efforts in taking the gratifying action. In other words, when I tell people "no problem," I'm expressing that my behavior hardly necessitated thanks. If anything, "no problem" is kinder than "you're welcome" insofar as it diminishes the perceived worth of the instigating action.
I tend to prefer "No problem", in the sense of "You now owe me immensely, and I will see that you repay this debt, when I find the right time and place for you to take the fall for one of my mistakes." I also tend to be very sarcastic. Seriously, I've never put much thought to this phrase, although it rolls of my tongue all too easily. I do though, like the sound of "no problem" paired with, "I'm glad to help a friend like you, and am glad to be helpful as you've been to me." Something like that.