on PVE servers I couldn't care less.
BUT on PVP server summons to dungeons or bosses or quests or well.,... SUMMONS. should not be implemented. IF you want to kill a boss/do operation with your guild, you should plann those events (even if its just a 30 min warning in guildchat or something).
Right if someone wants to do pve content they should spent as much time as possible not pvping, god knows them sitting for hours in fleet will make them so able to interact with world pvp.