Because the author has an agenda, he's a dynamic typing and unit testing proponent. Do not expect anything even distantly resembling any kind of an objective science from someone who clearly is not interested in facts.
This is pretty much a personal attack and those are not allowed here.
Also, what you're saying doesn't match my recollection of luu's writings on this topic, which is that he's mildly in favor of static typing but changed his mind somewhat after looking at the dismal state of the evidence.
Who is not interested in facts? Did you even read the linked article? If you read nothing else, at least read the summary. He makes very very clear that he is a static typing proponent.
