The post's entire point is to say make all actions snappy. That doesn't mean you can finish loading a video instantaneously, it means you can acknowledge the user's request to start loading a video instantaneously.
Waiting for termination of a loading indicator on a web page is irrelevant to this post, it's a tangential topic completely.
"content" in the post is not referring to web page content, it's referring to UI content. We're not talking about content generation in the web page sense.
64ms is still not something you're going to be "waiting" for.
Typical human reaction time is 200ms or so. This effectively means that for 200-264ms you're not priming to repeat the action or wondering whether it "took", because there's an immediate response and the action itself does something useful quickly.
In contrast to "not-so-snappy actions"? Snappy actions.
As I tried to say before: Instantaneous feedback is great (even necessary) for first time users. But once I get used to an app, waiting for the termination of a loading indicator is just as annoying as waiting for {page|script}-{load|parse|eval}.
Edit: > This idea is not in the least bit controversial.
I agree that content generation in one-digit milliseconds is not controversial.