There was a big push on r/drugs for Erowid. It's a great website and a great idea, and I'm not a big fan of "effective altruism," but I can't help but think there were probably some more deserving charities. Oh well. It's not a negative.
Someone at a Richard Stallman (of the Free Software Foundation, another organization on the list) talk I attended asked him why he is so focused on the politics of software, when there are many political problems that are more fundamental and need attention. His answer was something along the lines of acknowledging that free software is not the most important issue in the world, but it was important and was what he knew best. I think most of the organizations in that list are in the same boat; they are worthwhile but not things most of humanity is passionate about. They are things prominent subsets of reddit users are passionate about.