For the small number of dependencies any of the projects I work on have, I find it easier to download the dependencies in a browser, and just copy them to the projects I'm using. I understand this is heresy.
Have you used Bower? I haven't but I watched a video of some guy speaking of Bower who pretty much said the same thing you did but changed his mind after trying it out.
I haven't tried Bower yet but kept that anecdote in mind and plan to try it to see what all the fuss is about.
From my understanding, a single command will take away all those intermediary steps between deciding to use a library and actually using it. No need to navigate to the project's page, looking for download link, downloading it, extracting and copying to the project directory.
Sounds good in theory to me; just haven't the chance to try it yet myself. Mostly because npm happens to have everything I would have used Bower for.
"Small number of dependencies" being the operative phrase.
Try managing a complex single page app with deep dependency graphs and each node in that graph versioning up independently. Not sure how your approach would scale there.
