I'm just saying that they reinvented most of the stuff that you get from clojurescript by default, and they did it in a more awkward manner because they tacked it on top of JS.
Like they already have a JS preprocessor, have their persistent datastructures, etc. and have to deal with a lot of stuff they wouldn't need to deal with in a functional programming language.
So I'm going to try and answer your original question:
> I always wondered why Facebook didn't just go all-in on clojurescript when they did React, they have the resources to deal with any compiler/technical issues, heck they could reimplement the compiler themselves they already maintain a bunch of PHP VM/language stuff. It does everything react tries to do but better and by default.
You're not correctly estimating the resources required. Every Facebook endeavor I've heard of was an attempt to keep their millions of lines of production code unchanged with the added benefit to have new code be better. (eg. PHP->Hack, Untyped JS->Flow, DOM Manipulation->React, ...)
That said, perhaps you're not familiar with these types of codebases and aren't quite grasping the magnitude of code change that would first be required for Facebook to go "all-in on clojurescript". If you haven't had the opportunity to participate in a codebase of that magnitude, there aren't really words to describe it to you. Just know its multi man years worth of effort. In practical terms its not possible because a business also needs to iterate and release new features.
Like they already have a JS preprocessor, have their persistent datastructures, etc. and have to deal with a lot of stuff they wouldn't need to deal with in a functional programming language.