The article doesn't say "interviews don't work". It says "interviews don't work for me, so I get my foot in the door another way". He's not really arguing that they are a bad idea in general, but he simply suggests he'd do better with a test project.

I think you're going too far the other way. Your argument basically seems to be "if you can't pass an interview, there's something wrong with you". Which is probably true. On the other hand, there's dozens of personality quirks (some of which are worse than getting nervous in job interviews) which wouldn't show up in an interview.