I think you're missing my distinction here. Yes, bower will clone from GitHub, but of course only the packages you actually use; in the same sense that Go can import source from GitHub repos. These repos are storing code and using GitHub as intended.

But CocoaPods/Specs is the equivalent of someone collecting all possible packages you could ever use in Bower in one big GitHub repo.

It's only the package metadata (the spec) though, same as Homebrew, it's not like the package code is pushed to the repo.

Though I wonder if the actual project-fetching is similarly daft.