In my group(s), we make no real progress toward the overall goal unless I take the role of leader (no matter what PC I'm playing). The two groups are a little different, though, in that in one, any action at all simply ceases if I don't push it along. In the other, lots of roleplaying gets done, but the group gets smacked by decision paralysis.
In the former, I recently created a PC who simply cannot be the leader, in the hopes that someone else would step up. We also recently recruited a more active player into the group ... that might work out, if he doesn't go overboard.