Your comparison of mutable programming to the use of goto and unhygenic macros would suggest that mutation is a similar type of dinosaur to be culled.

>You've never tried to compose multiple asynchronous event streams of complex data types from different subsystems into one single user-facing unified presentation, have you? Your assertion is simply not true. Such feat is way simpler in functional reactive style, and a true nightmare in an imperative multithreaded program. That's why web frameworks are evolving to handle more and more reactive functional patterns for compositional asynchronous tasks.

Imperative programming with state is simple. Programming asychronous event streams of complex data types from different subsystems into a single unified presentation is complex. Functional programming claims to have abstractions that make the latter more simple than imperative programming, which may or may not be true.

The use of functional reactive style in React (I do not believe Angular relies on this) is probably driven by JavaScript having atrocious scoping rules and the general Web / DOM stack being full of hacks and badly written APIs. The hacks that are still present in React make it seem like this will just be yet another layer of cruft that is the front end, alas.