After finally completing this dungeon, I can safely say unless they plan to have these mobs drop something like silver pieces or guard some chests with gear there is literally no reason to fight all of it except to get some sweet addtional gear damage, ya know if that's your thing.
They could make this like Dynamis in FFXI and random mobs drop currency on occasion, that would get people killing them and solve the issue of not enough gil being generated into the system.