This guy's metaphor completely and totally breaks down when he begins comparing today's space agencies to China and Portugal of the 15th century.
Apollo and the shuttle weren't caravels and galleons. To extend the aquatic metaphor here, Apollo was our most sophisticated floating log at the time, and the Shuttle was our first real attempt at tying some logs together so we could ferry supplies back and forth to a little sandbar (the ISS) we created 15 feet off shore. If we ever try for Mars, we'll probably be sending our first dug-out canoe.
China and Portugal knew how to create decent and practical sailing ships. We barely know how to get into space, much less have anywhere near the technology available to exploit it properly.
And most importantly: THERE IS NO ONE AND NOTHING OUT THERE TO TRADE WITH. No developed resources and easily-available goods we can just pluck out of the metaphoric ground and take back. Everything up there has to go through a very complicated and expensive process of development before it becomes useful and profitable.
The better metaphor for the current state of space development may be if Portugal was the only human settlement in all the world, and its only watercraft were floating logs. The China vs Portugal argument might work in two hundred or more years, when we actually have the space-going equivalent of caravels and galleons, but for right now just finding a decent oar we can paddle with is quite an accomplishment.