This is a common strawman, with several examples to disprove it:

- https://github.com/cujojs/curl - https://github.com/montagejs/mr - https://github.com/substack/wreq

to support CommonJS in the browser you either 1) require that it is wrapped (and therefore isn't really CommonJS) or 2) you XHR it, wrap it yourself, and eval. That's it's possible to work around the problem doesn't discount that it "doesn't work well" in browsers.