its because moron dev thinks luck > skill all the way even on coil. thats why^^ heavensward is hopefully fixing that tough. for some reason many asian devs seem to be RNG addicted maybe they have a habit on gambleing there idk. running coil and clearing the hardest content on endgame and not getting something to show for it is bad game design. simply true bad design. players cannot "fix" bad luck with rng if there is a weekly lock. its either rng and endless runs allowed like tower or weekly lock and NO rng involved. together it makes raiding sad.