So could you list those problems?

Namespaces, for one.

Namespaces in Maven seem like they're clunky. The pseudo-DNS thing where the first section is an actual domain but the second is whatever you want is quite janky, as is not matching the namespace to the package. Plus domains are transferable themselves and it seems like a bad idea to use them as identifiers.

Not to say that npm shouldn't have had namespaces by default, but I think there's good reason not to blindly do everything the way the Java community did.

> Not to say that npm shouldn't have had namespaces by default, but I think there's good reason not to blindly do everything the way the Java community did.

I'm not saying that they should have blindly copied Java, but they should have had something.

One issue is npm will allow arbitrary code to execute as part of an install script for a package, which allows a class of attacks that aren't possible in the maven world.