This take is annoying.
But it's also not entirely @gruber's fault because the media doesn't really talk about the Fediverse, and when they do, it's as a synonym for "Mastodon".
How would @gruber know about the massive development efforts to build more user-friendly alternatives to Mastodon?
No one in the media talks about the growth of *key apps, and how they're now the #2 most used Fediverse platform.
That story isn't being told.
Whenever I tell people that Mastodon isn't the Fediverse, the Mastodon stans start saying, "Oh, you sound like a guy who's complains that Linux isn't called GNU/Linux."
No, there's a massive difference.
To most people, whether you call something Linux or GNU/Linux doesn't affect the user experience of using the OS.
Referring to the Fediverse as "Mastodon" definitely affects the user experience of using Mastodon.