Looking at the author bio, I can see he's very invested in the Blink project so it's difficult to shake the feeling that by arguing for "browser diversity", he's simply pushing for increased Blink dominance.
If one truly wanted to get more diversity in the Browser space, the number one objective should be getting Google to divest from the Chrome project. This would finally create space for other players to come in and have real influence over the future of the web.
As it is today, everything Web-related gravitates around what Google wants. Apple is not playing ball, and so Google is getting the community to push regulators to intervene and make them kneel.
Well, that's my view at least, maybe I'm too cynical.