I think it would be fair to say that a monetized third-party reference wasn't exactly what WordPress had in mind when they really started documenting the core in earnest in recent years. Especially when you consider that Hookr is piggybacking on thousands of hours of volunteer effort. Information should always be free as in beer, but not at the direct expense of one person's volunteer effort for another's monetary gain.

Yes, obviously, Hookr looks to be much more than a reference for the core of WordPress, but let's not forget where it started and will continue to heavily focus.

How interesting that Mr. Sanford's complete unwillingness to contribute back to the official effort that Hookr almost entirely relies on was glossed over as "friction". That inaction sends a powerful message to the hundreds of volunteers who work on WordPress core documentation that their time and effort is more valuable than they realize.