The Dalai Lama is talking about the genocide of the past 50 years, not just the past 50 days. You can't deny that there has been genocide in China! It isn't just the Tibetans, of course -- lots of others were killed, and it isn't just China -- lots of countries have genocide in their history. The difference is that Tibetans did and do have a markedly different culture that has been dismantled and decimated. I won't argue that it's anyone's duty to preserve other cultures, but it does explain why they're so upset.