Oh, I see! That clears up a lot for me. I used to think that the proxy baptism was more of a forceful thing than simply offering the dead the opportunity for baptism. I don't really agree with that particular approach to conversion, but it does make a powerful symbol.

I guess it's a cultural difference between churches-- Anglicans don't really have the same level of ritualization, For the vast majority of church members there's only baptism and confirmation, though some people choose to study theology and get ordained. Ceremony isn't as important. I guess that's why LDS seems strange from my point of view, but I definitely have a better understanding of the reasoning now.