That's what you get for not using the metric system.
As you realized in your post a little later, it has nothing to do with the metric system, and if anything in this the US is more "metric" if you will, then the EU.
And the original article has nothing to do with the difference between short scale and long scale.
Not being used to thinking in terms of multiples of 10 (or 1000) for all measurements might have a fair bit to do with it.
I've heard the idea bandied about that we should just drop the ambiguous names (w.r.t., the whole long/short scale thing) and start using scientific notation. It is much more obvious that 10^12/10^6 = 10^6
Ten to the power of six? That's like a cube, right, because a cube has six sides, right?
Part of the problem is trillion sounds just like billion. Your brain hears it and thinks "way bigger than a million", and stops calculating right there. I imagine most people would tell you a "zillion" is a million millions, though.
You've probably heard it, but there was a joke floating around before the last election: the secretary of defense goes to see the President and says Sir, there's been an unfortunate terrorist attack in South America. 5 Brazilian soldiers died. The President thinks about it and says, That's a real tragedy. And, ah...how many is a brazillion, again?