Well I mean it wouldn't have been a big deal, if the do block binds to the outermost, then in most cases just would get a compiler error since usually a private

Well I mean it wouldn't have been a big deal, if the do block binds to the outermost, then in most cases just would get a compiler error since usually a private fn/0 doesn't exist. Still though in the early days elixir more strongly preferred no-parens, so avoiding that is understandable.