I myself don't have too much to add, but in this 80,000 hours podcast with Will MacAskill they do discuss it. (if you don't want to listen to the whole podcast, you can look up the transcript.
I, like probably most reading this, am someone who strongly values reason and believes that helping others is a good thing.
This is why many people choose to 'join' EA: They find EA somewhere, think that the ideas make sense and seem true, presumably because it aligns well with their values and consider it right. The reason-based approach makes sense to them.
But isn't the procedure similar for following any community? Imagine I am looking for meaning, so when I stumble upon a guru which aligns with (some of) my values, I integrate myself into that community...
Let's go!
Maybe you should cross-post it to LW too?