3) An appstore app will (or at least could) continue to work even when I don't have network connectivity. A Web app won't.
If you think the web is popular because it's a cross platform sandboxed version of Access (which is essentially what you were suggesting) then you're the idiot. There's only so many useful applications you can make by simply storing and retrieving very simple data locally.
But giving this article any credence is giving it too much credit. It's shock-blogging and nothing more.