Simply put: dependencies are code, and code comes at a maintenance cost. Thin abstractions, such as a this library, can be replaced by a function or two, which is a lower maintenance overhead because there is less code, you wrote the code, and all the code is being used.

IMHO, dependencies should be pulled in for things that would take you weeks to do correctly. Avoid pulling in a dependency for something you can do yourself in 5 minutes. So I would pull in an http library if it actually did the mechanics of http better than the one in the stdlib, but not one that just wrapped it up for me a bit.

For me, that's not a Go thing, that's just an I'm Older Now thing.

Also, snarkily, dependency management is a mess in Go right now; none of us have any dependencies because we can't figure out how to do it. :P That is definitely a hole right now (though it's starting to get plugged in 1.5 with the /vendor directory) and is definitely exacerbated by the core team not being able to use any solution they could provide for the community.