Another use case, though I admit not the top priority of anyone here, is that of assignment checkers. In most courses I took at the university, the person who checks the assignments says something like "you are allowed to use only this this and this libraries", in order not to mess with unknown dependencies from tens of students (I am talking about advanced courses, where the method I use to solve the problem is unimportant or only requires explanation). With this statement they can simply state "you can import pip". 

Of course it still requires privileges and network connection, etc. And yes it can be solved in other ways automatically, but the fact is, it isn't.

We get the side benefit of making more people aware of pypi and actually using it; many people are not aware and/or don't bother using it. 

In other words, the language will encourage people to use pypi. It might has its downsides (of introducing possibly unneeded dependencies) but I am under the impression that using pypi is something that is considered A Good Thing, in general.