It seems like http://libraries.io/ is looking in npm Pypi and the like, but doesn't look in Github and Bitbucket.
I know a couple of open source project that have their own library ready for reuse, but http://libraries.io/ doesn't find them because they are not for reuse for npm, and the like. And if I know a couple, there are probably thousands. These libraries are not not re-use first, but project first, re-use second.