Isn't that exactly the kind of institutional arrogance that the GP post was highlighting?
OK, some web sites might still be fundamentally dependent on Google. Personally, I'd advise against relying on a business model based primarily on search traffic for a number of reasons, but of course everyone is free to try it if they like.
However, I somehow doubt big name brands like Microsoft or Audi or McDonalds would suffer irrevocable harm if Google disappeared tomorrow. Nor would major sites like Wikipedia or Facebook. Nor would all the popular forum/news aggregator sites, or the popular source sites that repeatedly get linked from them.
Perhaps more telling, I doubt any of the much smaller niche/hobby or family business type sites I know about would suffer greatly if Google vanished tomorrow either. The big G represents only a modest share of the incoming traffic in each case, and moreover the quality of that traffic in terms of engagement and conversions is relatively low compared to most other major sources. They are often beaten on volume by at least one order of magnitude by a single link from an influential blogger in a relevant field who is genuinely suggesting that their readers visit that site, or the equivalent via Twitter, Facebook, Reddit, Pinterest, etc. And that's before you count the viral effect, which can bump the difference to multiple orders of magnitude. Content is king, as Cutts has often said, but in 2014 good content can be found many ways without any help from Google.
I suspect this issue is symptomatic of a serious and long-term difficulty for Google search: their foundation is still basically the idea that you can judge the worth of a page by how many incoming links it sees. I'm reasonably sure that unless they have some shady deals going on with various popular social media sites, they don't even know about probably 90% of the incoming links to most of those little sites I mentioned, nor about 99% of the links my friends and family share to other people's sites. All they've got left is the public blogs and the assorted SEO tricksters, and that's not where a lot of people share genuine recommendations any more.