Progress trumps minor (even major) breaking changes any day of the week for me 
I think many people have come to Elixir and Phoenix in pursuit of something akin to perfection; a better way, and we love that José and Chris and the core teams of the various projects in the community (and even going back to Erlang with Robert, Joe and Mike) had a relentless focus on doing what they felt would represent the cutting edge in an as accessible as possible way.
Although Elixir and Phoenix (and projects like Nerves and Scenic) will I’m sure mature very nicely (you could argue most already have), I can’t ever see them stagnating, because it seems to be in the blood of those involved to keep introspecting and evolving 
