&quot;It does actually - you update the state, then React propagates the changes for you through it&#x27;s props mechanism.&quot;<p>That&#x27;s not all that different from what DispatchMessage does in the Win32 API.<p>Anyway, I think that what FRP, React, and Win32 all have in common is a reliance on explicit <i>local</i> state.  Components are not supposed to maintain references to other components and send them messages directly; instead, components are supposed to pass messages back to the top-level event loop of the component hierarchy, which then dispatches them to the appropriate subcomponent, which is supposed to take the appropriate action based only on information in the message and its own local state.<p>This is in contrast with later OOP frameworks like Swing, MFC, NextStep&#x2F;Cocoa, or the DOM, where it&#x27;s common to hold a direct reference to another component and then update it via observer.  These hold implicit global mutable state; the state of distant components in the tree may be silently updated in response to an event firing in some other component.<p>The trade-off here is whether you want spaghetti code or ravioli code.  Functional frameworks (FRP, React, Win32) tend to locate logic for the details of <i>what</i> should change outside of the components themselves, which focus only on <i>how</i> it should change.  That keeps component logic simple and prevents unexpected side-effects, but means that the code for the controller itself can become ginormous.  OOP frameworks tend to move logic for <i>what</i> should change into observers, which then reach across the component tree and update a number of different components directly.  You break up the logic into a number of bite-sized pieces, but there&#x27;s no way to see or predict what the effect on the system of a whole of an event will be.<p>Interestingly, Polymer&#x2F;webcomponents goes back to OOP-style ravioli code.  I suspect that like the rest of the computing world, we&#x27;ll see a see-saw effect on a roughly 4-5 year cycle, so maybe around 2018 observers and mutable state will become popular again.