babel handling import to require makes sense, but surely babel is not handling the css side of things. is it enough to just have babel and webpack-css-loader and everything "just works" ?
webpack handles bundling multiple files into one file or loads multiple files in chunks depending on size of your app. This includes css and js. I wouldn't say it just works as webpack is confusing at first at how you set this up for dev and production builds. I constantly refer to @bebraw SurviveJS - Webpack https://leanpub.com/survivejs-webpack and I highly recommend it :). There is also a gitter chat dedicated to this book regarding webpack where the community will help with questions https://gitter.im/survivejs/webpack