>Why does it matter that a Guardian article was the thing that gave the writer the missing link?

Why? Isn't that kind of obvious? He says he fears that it will enter public life as a kind of political vocabulary. It was in the Guardian, read by millions, shaping discourse. It already entered public life at that point. It's relevant.

He's also implying that the original Guardian article missed the significance of the detail - indeed, this alleged inattention from mainstream media sources is part of the justification for writing the piece at all.