Why Elixir over native Erlang? Nobody including the original piece seems to address this. Is it just a subjectively nicer syntax?
Elixir makes sense because it is a lower barrier to entry. This is a very important factor. It is one of the main reasons why node.js was so successful in reaching a large audience. It is why Go is more popular than Erlang. They are often used in the same domain and Erlang is arguably more powerful. People still choose Go however.
I was really into Prolog back in the university days, to the point of being into logic programming competition between universities.
Got to understand Erlang at the first try, when reading about the language or watching web talks.
It pretty much depends from where one is coming from.
In terms of elegance, I've never written anything that surpasses Prolog.
For a defined subset of problems.
Also most companies HR departments will ignore CVs without an EE or CS degree from those same universities.
Also learning erlang was much easier when you had some basic idea of prolog. Clauses did not seem so weird and once you understood how clauses work you've basically got 80% of the language nailed.
What I don't really understand though is why erlang didn't go all the way. Why take only surface level features of prolog and ignore the really cool parts?
However, in terms of barrier to entry for developing in, I actually think Erlang's is lower. People tout Elixir for its syntax being similar to other languages, but that's a detriment, not a benefit. Erlang and Elixir, both, require you thinking in a way most other languages don't. With Elixir, and the language looking familiar, you're tempted to try and shoehorn your existing knowledge, practices, etc, into an Elixir shaped package, and that leads to less idiomatic code, more surprises in how things actually work, and sometimes even more brittle applications than how they ~should~ be (though having a decent supervision tree means they'll probably still be better than what you'd have had in those other languages). Using Erlang, though, you relearn from scratch. It's a small language and that syntax isn't really a huge barrier; being forced to code in a language that shares so little with what you're experienced with means you're likely open to new paradigms, and will pick them up instead of trying to reuse your existing ones.
At least, that was my experience with Erlang, compared with Scala/Akka (which I tried first, and ended up with a lot of OO, non-functional, non-parallel code).
The Elixir devs are also fairly smart people and the community seems cool which shouldn't be underestimated.
That being said I have a Prolog background so stock Erlang looks fine :D