One limitation is that in an Erlang/Elixir node you can only have one version of module. This makes it difficult to run multiple applications if they happen to both use the same name for different modules. The confusion would be truly wonderful. 
When we were designing Erlang and the basic ideas of how to use the language features we were thinking more along the lines of operating systems rather than of applications. I tend to think of it not so much as a language with concurrency but more of an operating system with a languages.
Have a peak at the GRiSP.
