The point of the article is that when your experience translates well, you should do that. When it does not, you should not.
That I would agree with. The article states Success in an area is not transferable. You need concrete domain knowledge.
That just seemed a bit too restrictive. Transferable skills can be very non-specific. A drug dealer might now more about word-of-mouth marketing than a CS whiz kid who writes very smooth iPhone apps.
a) Your experience from a previous career might translate well to the new one.
b) The cost of developing an iPhone app is now low enough, that you can give it a shot and see if your idea is any good, for example by virtue of a)