I've watched Elm since its inception when Evan was posting about his experimental FRP project on r/haskell. (Yep, Elm actually started as a functional reactive programming language. That was before The Elm Architecture was developed and all that terminology was thrown out.)
As the project has developed, I have certainly wished Evan had taken a different and more open approach to leadership. I think Elm could be 10x as big as it is right now if he had aggressively encouraged community involvement instead of trying to lock the language down so much.
That said, it's completely mystifying to me how Elm is surrounded in so much drama, and it seems implausible and unreasonable to attribute it all to Evan. In the early days, it started getting hate from some hardcore Haskellers who felt that it needed more sophisticated language constructs. They would have converted it into PureScript, which clearly has never gained any widespread traction either -- perhaps less so than Elm despite all the drama. This is probably one of the earliest sources of conflict where Evan went against what a vocal minority wanted. Since then, it seems to have just snowballed, with the Elm team getting more locked down and vocal users becoming more and more upset about not being involved.
At the end of the day I don't really know what to make of it. Elm would not be Elm if Evan had listened to all the aggressive requests to make Elm more like Haskell. It would still be stuck in FRP-land and 99% of web developers wouldn't be able to make heads or tails of it.
What I will say is this. I have written some internal tools in Elm, and it's one of the best languages I've ever used for web development. It's a revelation of what the web ecosystem could look and feel like in a parallel world. Years later, I would still pick Elm for such projects because nothing else comes close from certain perspectives. I can always go get the normal experience with TypeScript and React. Elm is what I choose for self-contained applications where I don't need and don't care to deal with all the general chaos of the web world. And, personally, I doubt Elm would be this way if the early naysayers had gotten what they wanted.