Nice thing is, Reason converts lossless to OCaml, so all the ML fans can profit from the money FB pouring into the ecosystem.
Of course, F# has not always been the favorite lovechild of MS, but the OCaml ecosystem does not seem to be in a particularly stellar state either.
Maybe that's a good thing for Facebook?
From an individual standpoint, there are some unique aspects of OCaml that we like a lot. The properties of BuckleScript for example (tiny output, great js interop, fast simple compilation).
No doubt that the ecosystem could be improved, but that's what we're here for and what we're willing to do.
I'm not entirely sure what you're referring to, but OCaml has been around and used for real work for much longer than F#. I'm not sure it's so clear cut.