You can say that for almost any language that's not C/C++, C#, Java, Python and JS. Rust is just barely beginning to become "corporate". Even Ruby, which is pretty mainstream, has relatively few jobs compared to the big corporate languages.
I kind of like that Ruby is still focusing on single developer/small team productivity.
Your list is at least missing PHP, Typescript, Swift, Go, Lua, Ruby and Rust though.
But Ocaml really doesn't belong anywhere close to this list.
OCaml runs software that billions use, is used by financial and defense firms, plus Facebook.
But Lua? By that metric I'm throwing in every language I've ever seen a job for...
R, Haskell, Odin, Lisp, etc...
Edit - this site is basically a meme at this point. Roblox is industrial strength but Facebook, Dassault and trading firms are "hobby". Lol.
Also, I'm not dissing Lua, there's just irony in calling Lua industrial but not OCaml...
Do realize that luajit for years was bankrolled by corporations.
Lua, Bash ... these are birds of a feather. They are the glue holding things together all over the place. No one thinks about them but if they disappeared over night a LOT of stuff would fall apart.
The most famous example being World of Warcraft, but it's far from the only one. If you play, or have played, games, you almost certainly have run software built with Lua without realizing it.
It's not because a language isn't relevant in your personal coding niche that it's not industrially relevant.
OCaml's use is comparatively very, very narrow.
And, in case you are wondering, I have absolutely nothing again OCaml. In fact, my first ever programming language was, as a significant fraction of French engineer from my generation, the “Lite” dialect of Caml. And I suspect that its OCaml heritage is a significant fraction of the reason why I love Rust.
But being used by exactly one FANG company, a single finance one and allegedly a defense company (aren't you confusing Dassault System with Dassault Aviation ?) isn't enough to change its status, especially when it's not the dominant language in two of those (AFAIK Jane Street really is the only one where OCaml has such a central place).
Dassault Aviation makes the planes themselves. All Dassault companies are under one umbrella anyway.
The OCaml website lists a bunch of other users.
In my opinion, none of that really matters, any single one of those uses proves it's utility... Facebook Messenger alone is probably used by more people than every piece of Lua software ever made though.
First, Dassault Systèmes doesn't fall "under one umbrella" with Dassault aviation, it is an independent public company (with the Dassault group having minority shares in the company). And just because a software company has defense related products doesn't make it a “defense company”, nobody would ever call either IBM or Microsoft “Defense Companies”.
Then Facebook doesn't seem to be using Ocaml in Facebook Messenger, and instead uses its standard tech stack for that (the Hack PHP derivative).
The fact that Facebook has a developer-facing team building internal development tools with OCaml doesn't suffice to change the status of a language: since there are barely any Ocaml developers at Facebook, an Ocaml enthusiast would have to be very, very lucky to land an Ocaml job there…
And that's the whole point of the “hobby language” status: can you land a job using it or not, and Ocaml simply isn't that kind of language. And again, France has been teaching Ocaml to at least a hundred thousands of students over the years.