One suspects it's you who hasn't distributed or installed many modules on either python or node.
So many of the problems that python has, simply don't exist for node, because it finds modules in a bottom-up hierarchical fashion. That allows a single app or module to use modules that in turn use different versions of other modules, and not to worry about what other modules are doing, or how other modules are installed, or how node is installed, or what version of node is installed. This prevents the traditional "dependency hell" that has plagued devs for decades. Thanks to tools like browserify and webpack, the browser may also benefit from this organization.
On top of all that, npm itself just does so many things right. It's quite happy to install from npm repos, from dvcs repos, from regular directories, or from anything that looks like a directory. It just needs to find a single file called "package.json". It requires no build step to prepare a module for upload to an npm repo, but it easily allows for one if that's necessary. package.json itself is basically declarative, but provides scripting hooks for imperative actions if necessary. At every opportunity, npm allows devs to do what they need to do, the easy way.
In a sense, node and npm are victims of their own quality. The types of "issues" (e.g. too many deps, too many layers of deps, too many versions of a particular dep, deps that are too trivial, etc.) about which anal code puritans complain with respect to node simply couldn't arise on other platforms, because dependency hell would cause the tower of module dependencies to collapse first. node happily chugs along, blithely ignoring the "problems".
Personally, I used to be able to build python packages for distribution, but since I've been spoiled by node and npm for several years I've found I simply can't do that for python anymore. It is so much harder.
