Well they are actually separate modules, and if you look at rollup-babel you'll see the main reason it exists is to speed up builds. > Using Rollup then using

Well they are actually separate modules, and if you look at rollup-babel you'll see the main reason it exists is to speed up builds. > Using Rollup then using Babel slows down development, because Babel is much quicker dealing with small files than large bundles. But using Babel then Rollup often means you include helpers (e.g. classCallCheck) multiple times. They are two separate modules that you can plug into whatever build tool you want separately. But even if they weren't modular, is it that big of a deal? In my opinion what build tools I use means a lot less than where I'm investing my time in what I learn, and all of these JS tools are building to the ES6 standard. The idea being, that hopefully someday in the http2 + es6 future we won't need all these build tools, but that shouldn't stop us from building experience on them now.