What I like about buddypress is the privacy. You can have the outward frontpage showing the yearly schedule & upcoming events, but the discussions would be private and you’d have to register as a member.
If ALL I wanted was a forum, I would start a facebook group. But facebook forums can’t really be searched and they are bulkier to navigate. You can’t have a separate forum for leaders, boy scouts, and cub scouts.
A mailing list wouldn’t be perfect either, too hard to find Useful Pages and too hard for a newbie to find useful information.