I'm an actual OCaml programmer, almost daily, and I don't understand this objection. We use autotools and make as the build tool (but you could use ninja/meson, cmake or whatever), and don't bother with opam/dune. We properly package over 100 OCaml packages in Fedora. For anything else not covered by a package we mostly call into C libraries, which is very easy to do from OCaml.
I guess it depends on exactly what you're trying to do, but we've developed a large amount of complex software in OCaml this way.
I guess it depends on exactly what you're trying to do, but we've developed a large amount of complex software in OCaml this way.