This guy is talking about building mockups, and only mockups.
A prototype is a working version of all key features that can be used as if it were the final product albeit in a somewhat limited fashion (E.g. the edges aren't rounded)
A mockup demonstrates the value in a non-working fashion so people can respond to the general idea.
If you don't get mockup vs prototype right, it's pretty hard for me to value your opinion on these matters.
I find that it's helpful to evaluate ideas on their merits instead of quibbling over terminology.
Getting terminology right is important from "does X solve problem Z, and are X and Y the same thing when it comes to solving problem Z."
That said, this sort of flat prototype should be do-able in a few days for even the largest of apps.
So, I'm in agreement with OP — except on the timeframe :)
But if the obsession over the term is forcing you to ignore the point of this post, possibly this will help: a guy at Google apparently decided that the distinction was enough to coin the word "pretotyping": http://www.scribd.com/doc/62418833/Pretotype-It-Second-Preto...
(Even if the terminology doesn't matter to you, skim the book--it's free here and has got some great ideas).
Prototyping to solve problems is often the quickest. Pulling other people's teeth to reach that point is what takes weeks. :-)