[lisardo]

That is one of the most common complaints about iOS.

Unidirectional data flow greatly reduce complexity because you don't to reason about several places making changes of the state.

I'm programming Elm after 3 years of iOS and, man, it's great. The amount of code I'm reasoning about is always contained in a in single vim window. It's something that can be done in iOS, but it would require very high discipline. In Elm it came naturally.