title: ReactJS - Global state outside of components
body: <p>I've been reading and watching videos on Redux and seeing a lot of debate about managing state in components or with Redux.  What I'm not seeing is anything about managing state completely outside of components with standard global variables.</p>
  
  <p>For example, I could set a global state variable like this:</p>
  
  <pre><code>let state = {
     player:  {
         username: "BillyBob",
         score: 100
     }
  }
  </code></pre>
  
  <p>Then in a React component, I could have something like this:</p>
  
  <pre><code>incrementScore() {
      state.player.score += 1
      props.update()
  }
  </code></pre>
  
  <p>Then in App.js, I could have this:</p>
  
  <pre><code>update() {
      this.forceUpdate()
  }
  </code></pre>
  
  <p>I realize that I'd still have to pass the update function down through the tree, but I'd at least be able to set functions at the component level and not have to worry about passing multiple pieces of state and functions to child components.</p>
  
  <p>I'm new to React, but the only downside I can think of is not being able to require propTypes.  Is there anything else I'm missing?</p>
  
  <p>EDIT:  Per request that I clarify the question, are there any major downsides to the implementation above that I should be considering that would affect even a relatively simple app?</p>