Merlin,
There is no obligation because there is no rule maker that must be obeyed, and, apparently Gilder forgot to consult you before writing his book...
The point is, you can either try to understand what he is saying, or you can congratulate yourself for getting him got good down and dirty by attributing meanings to his words that he doesn't use, then debunking your own meanings.
It's a choice.
In my world, I seek to identify correctly before I judge. Identifying incorrectly does not allow one to provide good judgments.
But, as long as you are at it, you might want to debunk all of Google for not using your meanings, too. That should make you really feel good.
Michael