There are lots of reasons why making packages black boxes is bad. A package like the one you've described that uses its setup script to install more dependencies has many problems. Installing extra packages without informing the main package manager what you're doing means that the package manager can't recognize or ascertain important information about the packages. For example, if the extra packages would require more space to install than is available on the computer, the manager can't tell. If the installation requires no network access, there is no way to tell. If the packages require …