Why use a chaining API? (#87)

docs/FAQ.md

@@ -24,3 +24,37 @@ give you the power to confine these changes to a single package. Some of these p
 between ease of set up and black-boxing the configuration. Once you decide to make a configuration change,
 you are forced to maintain the entire configuration and its dependencies in perpetuity. We believe Neutrino
 represents a good balance between ease of set up and future extensibility.
+
+## Why don't presets use a normal Webpack configuration object instead of the chaining API?
+
+The Webpack configuration works well when it is embedded into a single project, and it is the only configuration
+file to maintain. Once the configuration is no longer co-located with the project, and needs to be extended or
+modified across different projects, it becomes very messy to make those modifications.
+
+For example, let's say that a preset instead used the Webpack object configuration and added an instance of the
+`EnvironmentPlugin`:
+
+```js
+config.plugins.push(new webpack.EnvironmentPlugin(['NODE_ENV']));
+```
+
+If you wanted to extend this plugin in your own project to add more environment variables, you would most likely
+resort to either adding a new instance of the `EnvironmentPlugin` by requiring Webpack yourself, or looping through
+Webpack's plugin array, removing the plugin, and re-instantiating it with your own arguments.
+
+```js
+config.plugins = config.plugins.map(plugin => {
+  if (plugin.constructor.name !== 'EnvironmentPlugin') {
+    return plugin;
+  }
+  
+  return new webpack.EnvironmentPlugin([...plugin.keys, ...customEnvironmentVariables]);
+});
+```
+
+This forces a much higher maintenance burden on your project, and this is only a very simple example. Modifying
+loaders created from raw Webpack configuration objects can be **much** more unwieldy.
+
+Using [webpack-chain](https://github.com/mozilla-rpweb/webpack-chain) affords Neutrino the ability to identify and
+manipulate parts of the configuration without resorting to object and array manipulation hacks, something not currently
+possible when working with raw Webpack configuration data.