I'm pretty sure that if you understand both Turing completeness and the practice of actual programming, then you know that in most cases the one has virtually nothing to do with the other. (Which is not meant at all to imply that the author of linked article understands Turing completeness, just that even though he doesn't seem to he could still be excellent at teaching programming.)
Then the question becomes "why is he talking about turing completeness, something that is either irrelevant, or that he knows nothing about?"
I mean it sounds very nice and fancy - but loop semantics and conditional jumps have nearly nothing to do with what he's talking about.