Except does it really say anything?
It doesn’t really add anything to an understanding of how ideas spread or change. Just a way to explain away behaviors that seem to not be explainable according by more traditional ethology or evolutionary psychology methods.
The means by which certain ideas spread and why, the manner in which concepts are “turned” to be metaphorically applied onto novel data sets, the process by which approaches are reformed/topologically altered to fit current needs … memetics approaches none of these. And these are the nitty gritty of psychology, sociology, advertising, propaganda, and even epistemolgy.