Why is minification not benficial in Node?

Thank you for considering my suggestion! While minified code might still have some minimal runtime advantages due to optimization heuristics, (even though the node team seems to be moving away from this approach, e.g. disabling function length based inlining), in my opinion the main benefit to be had is in the reduced bandwidth usage, and thus improved load times when serving web content, which doesn't apply here. Also, even if would be talking about a library that gets used in web pages, I'm of the opinion that minification should be left as a last step to the author of the application itself, not the library. (Or in case of a library that doesn't have to be bundled and can be included from a CDN separately, I think it's the best practice to provide a regular build as well as a minified version ending in .min.js, as many of the widely used libraries do.)

the main benefit to be had is in the reduced bandwidth usage, and thus improved load times when serving web content, which doesn't apply here

It does. The package needs to be downloaded. And since it gets stored to disk long-term, size probably matters more.

My 2 cents: the ability to drop into node_modules and (easily) read/edit the code of my dependencies is very valuable. It means I can try out potential changes or fixes in the context of my project without having to first clone the source repository, install its dependencies, figure out how to build it, copy the build files into my project, and so on an so on. I can also more easily debug it, either by manually inserting console.log calls or by using an actual debugger. In both cases, dealing with minified source that bears little resemblance to the original code is very painful.

FWIW: #391