I use Elm on two large websites in production with users.
Elm helps me come back to these projects after months and, in two cases, a whole year, and get immediate work done without recredentializing in the whole codebase (which I have to do with my React projects to a greater extent).
You definitely can't be a fragile developer to use Elm, and I think the small community size makes people feel like others are obligated to listen to their opinions. Meanwhile they don't expect this from an ecosystem like React because they know nobody is going to listen to them, the ecosystem is just too big with too many people with hobby horses.
I've patched the compiler one two occasions for the 0.19 release. One was to allow me my Debug.crash calls. Elm is updated so slowly that it's trivial to maintain your own patch. Though I ultimately factored out my two patches.
While TFA makes some good points, just like I can enumerate the downsides of all technology that I use, a large bulk of it is just emotional catharsis. And I think this kind of exodus is a good thing. A lot of the people who supposedly leave stick around like a turd circling the drain just to give their aggressive two cents any time something negative can be said about Elm. I've always felt that to be most tiring of all. Kind of like the people who show up in every Typescript-related thread to say how static typing is for lazy developers and what not.