From what I can tell, it's actually a teeny-tiny number of people, but they get disproportional media coverage for reasons that should be obvious considering the interests of those doing the covering.
FWIW, while I've not met many misanthropic greens in real life, about half of the greens I've met on the Internet range from mildly to extremely misanthropic.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.