Other than its wide usage and adoption, I don’t think Java has any main advantages over the other languages. I believe the main purpose of creating various SDK’s was to make it as easy as possible for new developers to start developing on Zenon, in an language they’re most familiar with. As far as I understand that list of languages was decided upon in the Zenon SDK Status thread. So please don’t quit OCaml/Haskel is not on the list 
You could argue why create an JS and Typescript SDK version if Kotlin is downgradable to both. Wouldn’t Kotlin be enough to serve 3 other SDKs?
If you want we could discuss this issue with a wider audience and let the community decide whether its worthwhile to continue?