Not quite -- the rule is pretty simple: Implicit function calls associate to the right, to the end of the line (or the end of the trailing block). This allows you to write code like this:

    console.log inspect value

    model.save(attrs).then ->
      ui.update attrs

    rect.scale height * factor

... and have all of the results come out correctly, while leaving the code readable. If the rules were "more math-like" as you say, then none of that would work. Perhaps it would harmonize with special libraries that used functions (automatic-partial-application a-la Haskell) in a different way than JavaScript does ... but that's not the world we live in. It's gotta harmonize with JS functions as they exist.