Well, there are, of course, a number of reasons, but perhaps the primary reason is because we're still organized as a species in the same way that we were organized 200 or 300 years ago.
Pa, postoje, naravno, brojni razlozi, no, možda je glavni razlog to što smo još uvijek  organizirani kao vrsta na isti način na koji  smo bili organizirani prije 200 ili 300 godina.