I put all node functions I might want to re-use in other projects on NPM by themselves (though this also usually pushes me to make a lot of unit tests for each of them, which is a nice benefit). I'm not really clear on what's insane about re-using a lot of small modular parts. This is way better than copying and pasting functions between codebases, and then trying to keep them (and their tests) all in sync.
Node/npm is terrible. Look at Popcorn Time. This client app has over 4000 files in npm_modules. Most of them totally unneeded, and many of them tiny and for things that should be in a stdlib or rolled with others.
I think it's the same kind of folks that create a huge Java object model, always one file per type. Gives the feeling of being big and doing real work, even when you're not.