Honestly? If this were back-end programming I'd agree, but as someone who's done a tremendous amount of front-end programming, the guide feels spot-on.

Sure many of these questions are "quirks of history", but your job as an effective front-end programmer is to know them so your site works everywhere where it's supposed to, and you have the knowledge to make the right trade-offs between legacy support and future maintainability. Front-end programming really is much more about sheer accumulated knowledge than back-end is -- and it's not knowledge you can just "look up", because a huge part is knowing the gotchas in advance, in order to avoid them.

This shouldn't be a whole interview -- all the things you list are important too -- but validating a candidate's experience of all these "transient factoids" is not just valid but necessary, like it or not.