"Value of the middle of the path. Perhaps the engendering of genius is reserved to only a limited period of humanity. For one cannot expect the future of humanity to hold at the same time everything that only very particular conditions in some past time could produce-the amazing effects of religious feeling, for example. This has had its time, and many very good things can never grow again because they could grow from it alone. Thus there will never again be a religiously defined horizon to life and culture. Perhaps even the type of the saint is possible only along with a certain intellectual narrowness, which is apparently gone forever. And so, perhaps, has the highest level of intelligence been reserved for one single era of humanity; it came forth (and is coming forth, for we still live in this era) when, by way of exception, an extraordinary, long-accumulated energy of the will was diverted through inheritance to intellectual goals. This highest level will end when such wildness and energy are no longer cultivated. Perhaps mankind, in the middle of its path, the middle period of its existence, is nearer to its actual goal than it will be at the end. The energies that condition art, for example, could very well die out; pleasure in lying, in vagueness, in symbolism, in intoxication, in ecstasy, could come into disrepute. Indeed, once life is structured in a perfect state, then the present will no longer offer any theme for poetry whatsoever, and only backward people would still demand poetic unreality. They would then look back longingly to the times of the imperfect state, the half-barbaric society, to our times."
Friedrich Nietzsch, Human All to Human
Was reading this the otehr day and it occurred to me that perhaps this more than anything explains the rise and fall of metal. Art never exists in a vacuum and it is not simply down to the people involved why such an art failed.