This article doesn't even want to make the argument that is in the title. It's winking at the reader the whole time saying "Not Really".

I grew up around Detroit and there's a big difference between a city that has some tough times and a city that basically falls apart because of it. Detroit's industry fell apart, and then a hundred other factors (like race riots) led to the city no longer being a nice place to live. Even if Silicon Valley's tech industry were to fall apart, a lot would have to happen for it to start looking anything like Detroit.