It does look pretty weird if you have only ever worked in an imperative language.

If one can get past the initial impression though, they'll find it's actually a very simple, nice language. Much simpler than Scala/C++ and probably even Java these days. Also simpler than other functional languages like Haskell. I picked it up in about 1-2 weeks. There's very few gotchas in the language or hidden complexity. It flows well.

I'll also add the language suits the usage pattern. Pattern matching works very well with the gen_server approach. And the binary syntax is so nice if you need to deal with over the wire protocols, as is common in distributed systems.