We already use ocaml to write Hack, Flow and Infer, so just from a corporate standpoint, this move to incrementally adopt more of a language that's had many success stories internally makes sense.

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.