Yes, the reasoning in the linked posts implies that deep inside, humans should be as altruistic as you say.

This is not what the posts are about, even if this works as one of the conclusions. The idea that urges and goals should be distinguished, for example, doesn't say what your urges or goals should be, it stands separately on its own. There are many such results, and ideas such as altruism or importance of FAI are only few among them. Do these ideas demonstrate comparatively more visible measurable effect than the other ideas?