when you talk to pacifists, it actually usually doesn't generally come down to self-interest - or at least not anymore. conscription isn't a serious threat, and hasn't been through the course of most peoples' lives.
maybe that's the disconnect. maybe people are still interpreting pacifism through the lens of conscription. and, i guess you see a 75 year old protestor from time to time, right?
but, my experience with pacifists is that it's derived from the philosophical position that change is impossible. this has strong eastern roots in most pacifists i've spoken to, even if they don't really understand it entirely. but, you see it in native american philosophy, as well - and it has a kind of lost lineage in greek philosophy through the eleatics (parmenides and zeno), too. but, if you start talking to them, what becomes obvious is how conservative their pacifism really is. and, if it's a consequence of the idea that change is impossible, as it so often is, then what could be more conservative than that?