Anything that raises a flag and makes people think and consider alternatives to FB, Google, printed money, etc, is good activism. Whether it's from the couch or the armchair, is irrelevant.
The article identifies the risk that printed money will disappear, replaced with a few large credit card companies and banks so the government can monitor everyone's use of money. Since we're clearly already heading in that direction bit by bit, I wouldn't call it a fringe theory.
It is only fringe / extremist / conspiracy theorist when its a problem I don't personally have (or have not exerted the mental energy to fully understand). If it is affecting my life, it is serious mainstream business we need to take seriously.
That is a fundamental problem with online discourse. People put on blinders on singular crusades when reality is the combined effects of many, many forces influencing one another. Topically, the anti-encryption movement by governments is tied to broader totalitarian leanings by many traditionally republican states in the west, which has hundreds of influential aspects in all kinds of fields of business and society. And those leanings have correlations in everything from fearmongering to economic uncertainty to long running campaigns by certain interests that have lasted decades.
And then we get trapped in this rat hole of arguing over what is "serious" or meaningful, when in hindsight we can historically recognize almost all of history is the combined effect of many influencing factors not apparent at that moment in the past.
One of these things is not like the others.