While what the article says is largely true, he misses the point that, even if money were based on gold, and fixed to it, you still wouldn't be able to pay the US national debt. The money supply, as a value, cannot possibly pay for everything that exists simultaneously, of which the US national debt is just one fraction.
Yes, Nixon did have an issue when the debt grew larger than the value of the gold backing the money. At that point, the US could no longer back its debts using the gold, so it stopped that. Instead, it just backed it using the unique and legal power to tax.
And yes, the whole house of cards could collapse. But a gold backing wouldn't necessarily help that, as it would only help those with physical dollars in their hands. And, as Kuwait showed, just having gold backing your money is worthless if society completely collapses.