I agree with Nesov, Salamon, and Dorikka and suspect furthermore that the distinction between "altruists" and "egoists" that is drawn in the post is a confusion which doesn't survive careful scrutiny.

It seems to me that the people you call "altruists" are simply people who are attempting to have a particularly large impact on the long-term future of the world in a particularly direct way. But not everyone needs to work so directly on the most global scales, all the time; there is room (and likely need) for a division of labor, with some working more locally. For some (probably very many) people, improving themselves is among the most effective contributions to the future of humanity they can make.