This is overly America-centric. Like reading an ancient Greek historian equate the dissolution of the triumvirate with an impending disuse of the Corinthian collum. How could he know that Rome would use it ad absurdum? Well, it's both decorative and retains the efficient load bearing function of the Ionic and Doric collum. Why wouldn't it last? Similarly, there are more solid elements like nickel in the asteroid belt than there are on 100 earths (based on what we've observed so far). The first company or country to exploit the resources in the asteroid belt will be richer than anyone or any country in history. It is literally a floating gold mine out there. And, like the Greeks, the fall of their empire triggered the rise of another, as niches get filled by rule of necessity. Similarly, there are plenty of obvious and probably plenty of obscure nations or collectives ready to fill the niche left behind when the US finally putters out as a world leader, however long that takes. I don't have to try hard to imagine India or China filling that niche rather quickly. They certainly have the muscle and the expendable resources (and people). So while I agree that the current state of human space exploration is dismal, I think the author is confusing a corner with a dead end. Somebody is going to get to those resources or that money (or bring it to them by "catching" an asteroid), it just probably won't be Russia or the US who pulls it off.

Tl;dr - there is way too much unclaimed wealth floating in space to believe that no one will find a way to get to it.