ExtremeTech regurgitates the same figures and anecdotes from the articles in the Economist, Wash Post, etc. and then prognosticates. This is the world we live in now. We've turned all media into a big feedback machine. Has it beet this way for a while, even before the Internet? Perhaps it's just more apparent to consumers of media now that everything is so accessible.
Regardless, the result of the new buzz life-cycle is that even truly interesting stories feel cheap and fleeting; oh well, we'll be worried about something else is 3-5 days anyway.
This is one of the reasons I don't spend nearly as much time reading blog sites like ExtremeTech as I do reading things like the Economist and the Wall Street Journal etc. But I expect that for a segment of the market they don't bother with those other publications because folks like ExtremeTech boil it down for them. It does, as you note, create a kind of volunteer bubble for those folks, or an 'echo chamber' in the vernacular.
But to relate to the article in general which is extrapolating to a cashless society and offering up bitcoin as a savior (of sorts) to ward off the 'privacy annihilation' such extrapolations are always wrong. They are wrong because the systems they are extrapolating are more complex than a single variable.
Currently cash is less convenient than a card, and the drawbacks of using a card are not sufficient to discourage adoption. That calculus may flip however if either the convenience of cash goes up, or the drawbacks get more extreme. I suspect that cash will get more convenient when the digi-cash patents expire.
Regardless, the result of the new buzz life-cycle is that even truly interesting stories feel cheap and fleeting; oh well, we'll be worried about something else is 3-5 days anyway.