The role of José Valim, the creator of Elixir, can't be understated. He's everywhere, he's got his hands in many of the top used libraries, and he's incredibly welcoming and responsive to all the inane GitHub issues I've opened over the years.
People wrongly compare Elixir to Ruby, but I wonder if he decided to recreate the welcoming and newbie friendly community and leadership of Ruby.
(Chris McCord, the creator of Phoenix, seems like a pretty swell guy too)
Also, a note on the upstream code: Elixir and its core libraries are some of the few projects you get a quick answer to your issues and they aren't closed because they've gone stale. 18 open issues, 5k closed on the core repo is an impressive ratio these days.