What do people think about submitting other people's libraries to package registries like npm, bower, jam or other package managers?

I'm against it. I've come across a few circumstances where a branch submitted to the registry and then not kept up to date, or where there are multiple submissions of the same library.

Isn't it much better to ask the maintainer to submit it themselves, and until they do (or if they won't) just install the library directly from their repo (which is supported by both npm and bower; not sure about jam.)