It's not that the distributions appear in the Module List, which is unmaintained and dead, but that people have registered their namespaces in PAUSE so they can more PAUSE maintenance features and can set some meta-data in PAUSE. Most of the meta-data should probably be in the distribution itself, but most of them don't have that.

THE DLSIP categorization is still useful though, because it doesn't matter how many other modules use it for it to matter for one distribution. The categorization itself is not useful because of its source, and the same categorization would be useful in META.yml. Now that META.yml 1.4 is the current version, maybe we could add more categorization stuff to the spec for the next version. :)