My two (possibly annoyingly academic) cents:
The term "primitive" is a political problem as much as a practical one. The idea that a particular way of doing things is "primitive" while another is "civilized/sophisticated/advanced" is totally subjective, and historically based on colonial ideas of cultural hierarchy. At times, "primitiveness" was considered a sign of cultural or even biological inferiority, while at other times it was romanticized by Western philosophers, writers, artists, etc. The sum total effect was to say that "primitive" people (typically indigenous non-European people) were somehow simpler, more childlike, less intelligent, or just "lesser." The term tends to hang on today because we (mostly non-indigenous Westerners like myself) still find something quaint about it, which comes with all kinds of problematic baggage for indigenous peoples.
As far as the question of making a truly "primitive" bow, the primitive/not-primitive pairing is a false dichotomy. There's no such thing as the "true primitive" bow. Whether something is "primitive" or not isn't actually and either/or question, but a matter of degrees, or (if you want to reject the colonialist perspective altogether) a matter of style.