Technology (the product) can be decentralized. But the generation of ideas that create the products is a separate thing from the product itself. Many would say there is a geographic aspect to the generation of ideas... that people, for some reason, need to be in proximity to each other. When bright people work together they produce much more interesting things than when working in isolation from each other. And from observation, it also seems that bright people seek each other out. This isn't to say SV is great or doesn't have its issues, but it seems to attract the brightest people from around the world (and possibly 'parasites' as you mention, as well).

I don't think most places like Canada want to replicate SV... just the part about creating large successful tech companies. The article suggests this might be helped by allowing people to actually get and stay there. It's not really about 'centralized technology' but more about creating a culture where people from around the world can come together and make these things happen.