The author is critical primarily of Elm's governance and processes, and claims that these are what killed the project. I don't think that's entirely true. There was a recent interview with the creator of Elm here.
https://www.youtube.com/watch?v=0SUM4869ODc
I'd encourage everyone to watch that as a grain of salt to TFA. It seems like the project leader felt he was being taken advantage of, and was just not getting out as much as he was putting in. That's his decision to make and he doesn't owe anyone anything. If you want continued support, pay up.
Elm's governance and process are what made it such a delight to use. Instead of allowing the full spectrum of bad ideas in frontend development to slowly make their way into the language, the authors carefully curated a coherent set of good ideas. They said no to a lot of things, and cut out as often as put in. This is going to piss off a lot of people because it means saying no to a lot of people. Saying yes to those people would make the language worse; you can't have it both ways.