It is the subject of the article. My best faith reading of the original comment was that it decries the arbitrary nature of platinum - if we are calling it a $

It is the subject of the article. My best faith reading of the original comment was that it decries the arbitrary nature of platinum - if we are calling it a $trillion, why not make it out of anything? But the debt ceiling is itself a legal construction. People call it a "loophole" because of episodes of The Simpsons or whatever but the Treasury is explicitly given permission to issue coins of arbitrary value. The debt ceiling is itself a legal construction.