I've worked on lots of nodejs projects with 1-2k transitive dependencies. I've seen plenty of simple projects end up with close to 1 gig of files in node_modules. And almost all of those files are never used at runtime.

I'd be a lot happier with npm if tiny libraries took up less space on disk. Storing a local copy of each dependency's readme file, license file, package.json and test suite is overkill when the module itself is only a few lines long. Its also very common for sloppy package maintainers to accidentally ship binary files in their npm module (image banners for their readme.md, test data, etc.)

Npm should only download the javascript file for small single-file modules. Nodejs itself already supports this - if you have a javascript file in your node_modules directory, require() will pull it in like normal. The license might need to be prepended to the file in a comment block, but this could easily be done automatically.