I haven't read that post. But I think you could have said the same thing about things like global illumination - well, in terms of processor time - yet look at

I haven't read that post. But I think you could have said the same thing about things like global illumination - well, in terms of processor time - yet look at how much more advanced realtime lighting is today than a decade ago. As for artwork and disk space, grass for one can easily be procedurally generated.