This is really interesting although I'd postulate that it is the byproduct not of the Stone Age mind, but of the patriarchal one - a social system that first came into being around 6-9 K years ago and instituted social and class stratifications of all sorts, not only between men and women. Patriarchy is a "might makes right" social hierarchy which is maintained by force (where being stronger would be a real advantage).
Prior to that time, enforced egalitarianism was the prevalent survival strategy, prioritizing the wellbeing of the entire tribe or village. In current hunter-gatherer groups, this type of reverse hierarchy prevents anybody (usually a man) from getting too many ideas about his own importance. Group social pressure, including teasing and shunning put anyone with a big ego back in their place.
When (anthropologist Richard) Lee asked one of the elders of the group about this practice (of insulting the meat from a kill), the response he received was the following: ‘When a young man kills much meat, he comes to think of himself as a big man, and he thinks of the rest of us as his inferiors. We can’t accept this. We refuse one who boasts, for someday his pride will make him kill somebody. So we always speak of his meat as worthless. In this way we cool his heart and make him gentle.’
