Sorry for the very late reply! Ugh, time.
Yes, it is so sad. In my philosophical jargon, it is called epistemicide or just neo-colonialism. It is the marginalization and rejection of difference. It is so sad how the people who still harbor this knowledge internalised western modernism and the drive toward sameness so they see their own knowledge as inferior. So many people here where I live still know the names of these plants and their medicinal properties and so on, but they keep it to themselves because they feel it is inferior and "backward". It is really so sad.