How can you say that when there's no evidence for it? Abramov is a successful, respected programmer. Redux is a major contribution to the web. This article came out two years ago, and he doesn't appear to have ruined his reputation. On what basis is it safe to say he "has" to know any of the stuff he freely admits to not knowing?
Well, it's not ok. It's bad. It's irresponsible.
There is a lot of basic stuff on that list one has to know.