Well, the thing is, being an Official Faction Leader, requires some level of commitment to the server, and the game.
Like it or not, others rely on clear communication with or to you as an OFL, simply up and leaving is unacceptable, and should be treated with scorn by members of both the faction, and outsiders.
If you cannot care enough or find the time that you refuse to even let people know you'll be gone for an extended period of time, you don't deserve to be a faction leader in the first place.
OP + 1
Edit: Being an OFL affects more people than just your own faction