The web was designed for reading documents not to try to shoehorn an operating system into the browser.
Thankfully the mobile world is bringing back the desktop applications concept, while using the network for communication protocols as it is supposed to be.
That's the exact opposite position from what Kay said:
"...what you definitely don't want in a Web browser is any features.... You want to get those from the objects. You want it to be a mini-operating system..."
Essentially he's saying that the way we think of browsers is holding the web back. We could have collaborative WYSIWYG editing of Wikipedia or blogs, for example, but instead we're stuck with just reading documents.
Perhaps it would be correct to say that the web was designed for reading documents, but it shouldn't have been (at least according to Kay).
The web was designed for reading documents not to try to shoehorn an operating system into the browser.
Thankfully the mobile world is bringing back the desktop applications concept, while using the network for communication protocols as it is supposed to be.