Joking aside, at least some externals that prove to be very useful or even fundamental (like zexy's sigops or [z~]) could find its way into the core now and then. To me, Pd vanilla seems to be overly conservative in this respect. On the other hand, I like that the set of objects is rather restricted, it's just about a handful of objects which I think are really missing and shouldn't require a user to get an external library.
And when there are already good externals which do an important job, why not include them? For example, Pd vanilla got its own set of OSC objects recently (nice!), but they are rather awkward to use and have far less functionality then, for example, the mrpeach objects (Miller actually refers to them in the help patch).