Voltz was a modded survival modpack that had a lot of items that are in FTB. It failed because it wasn't exactly a Famcraft type server. The goal was to dominate other players, pvp was allowed at all times, so was griefing. Players were very annoyed at each other, resulting in various bans. I myself regret going on that server because me and another player were kind of enemies and we both said things we now regret (at least I do).
tldr: Modpack, players got mad at eachother, shutdown.
