[kikibobo69]

One reason for not having return, has to do with symmetry, which Scala is full of.

For example, val x = if(foo) { a } else { b }

This is a lot nicer than the alternatives, and I suppose you could force people to write:

val x = if (foo) { return a } else { return b }

...why, why? It doesn't really add much. Once you get into the functional mindset, it becomes natural how this works, and the occasional place where you are forced to add a return statement becomes a place where there is almost certainly code smell. No returns is basically one of those constraints that helps guide you towards more functional code with fewer side effects.