I think the answer to the article is simple: inertia.

It took the internet - one of the most useful thing ever invented in the whole
history of mankind - 20 years to go from being functional to being used by a
sizable fraction of humanity.

I'm pretty sure the story is similar if not longer for other useful technologies:
running water in the house, steam, electricity, the lightbulb, the printing press,
the computer, etc ...

In terms of recent, large-scale successes, Facebook and Google are probably
the things that spread the fastest in the last ~20 years. And both each took
close to 10 years to reach planet-wide adoption.

In other words: it simply boils down to the fact that most people have no clue
of most of what's happening in the world around them, and only start paying
attention to something new once a at least 5 people in their close social circle
has finally hit them squarely on the head with it.

You want to see bitcoin succeed ? Talk about it around you at every possible
opportunity, show it to your friends, demand payment in bitcoins for ever little
transaction you do. If you want to start a forest fire proper, you must light small
fires in as many possible corners of the forest as possible.

And yes: you're going to get weird looks from people who'll be thinking "what
a dork". Bear with the pain. People said the same thing to early internet adopters.
Who's a dork now ?